client/container: ethereum-based: support Etherscan V2, add more L2 chains

- Implements support for unified API via Etherscan V2 (ethereum-based)
  * All ethereum-based L2s are now accessed via single API endpoint
    - Chains are now available via chain ID
  * Updates API key requirement for `fetch` ethereum-based subaccounts
    - The API key's value must now be prepended with "etherscan"
      * Previously was prepended per-chain ("ethereum" or "polygon")
    - The API key is now *required* (can be generated at etherscan.io)
      * Resolves fatal error in Etherscan::parse_response()
      * Impl will now handle if:
        - Config's API key/value is malformed
        - Etherscan API key was not given
        - Etherscan response is fatal

- Adds support for more L2s
  * Arbitrum (One)
  * Optimism
  * Base

- Adds more L2s to existing accounts
  * Coinbase Wallet
  * Ledger Live
  * MetaMask

- Updates documentation
  * Update default generated `fetch` config
  * Update `fetch` usage help
  * Update README

client/docker-finance.d/container/fetch/fetch.yaml.in

@@ -1,6 +1,6 @@
 # docker-finance | modern accounting for the power-user
 #
-# Copyright (C) 2021-2024 Aaron Fiore (Founder, Evergreen Crypto LLC)
+# Copyright (C) 2021-2025 Aaron Fiore (Founder, Evergreen Crypto LLC)
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -48,17 +48,39 @@
 #            1. Visit coingecko.com to get the assets's ID
 #            2. Prepend the ID to the ticker (as seen below)
 #
-#   3. For account APIs, replace XXXXXXX... with your API-related information.
-#      Accounts below will provide unique details/caveats on API key creation.
+#   3. For account APIs:
 #
-#   4. Feel free to delete any unused accounts/subaccounts as needed.
+#      - Replace XXXXXXX... with your API-related information.
+#
+#        * See the accounts below for unique details/caveats on API key creation.
+#
+#   4. For blockchain-based APIs:
+#
+#     - 'key' format: blockchain1/API_KEY1,blockchain2/API_KEY2
+#
+#       * For ethereum-based chains:
+#
+#         - As of now, you *MUST* use an API key.
+#           Generate your API key at etherscan.io
+#
+#         - Use "etherscan" as the blockchain API, as its
+#           unified API is used for all ethereum-based chains.
+#
+#       * For algorand/tezos: currently no API key is required.
+#
+#
+#   5. Feel free to delete any unused accounts/subaccounts as needed.
 
-# NOTE:
+# Disclaimer:
+#
 #   The example wallet accounts/addresses used in this file:
+#
 #     - were picked randomly from the blockchain and are meant to be used for
 #       demonstration purposes only
+#
 #     - outside the realm of testing and development, have no association with
 #       the author or docker-finance or Evergreen Crypto LLC
+#
 #     - are not endorsements of the wallet's activity or tokenomics
 
 version: @DOCKER_FINANCE_VERSION@
@@ -170,15 +192,13 @@ version: @DOCKER_FINANCE_VERSION@
         #subaccount: "platform/{BTC,LTC,ETH,USDC,USD}"
 
       coinbase-wallet:
-        # API scanner keys can be generated at etherscan.io, polygonscan.com
-        # key format: blockchain1/API_KEY1,blockchain2/API_KEY2
-        key: "ethereum/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+        key: "etherscan/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
         subaccount:
           ethereum:
             - "phone:cb-1/0x10Bd3c5d536f69e87C8d4ECB49C01dDc9db4637b"
 
       coinomi:
-        key: "ethereum/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+        key: "etherscan/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
         subaccount:
           # NOTE: same account name can only be used with differing networks
           ethereum:
@@ -187,20 +207,22 @@ version: @DOCKER_FINANCE_VERSION@
             - "phone:coinomi-1/BO65GIBYYYUPK4KTQ32IRO5BE2H3VEFTK65GKI2GNHZYPNUMJKGJOFJWSY"
 
       metamask:
-        # API scanner keys can be generated at etherscan.io, polygonscan.com
-        # key format: blockchain1/API_KEY1,blockchain2/API_KEY2
-        key: "ethereum/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX,polygon/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+        key: "etherscan/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
         subaccount:
           ethereum:
             - "laptop:wallet-1/0x6546d43EA6DE45EB7298A2074e239D5573cA02F3"
             - "phone:wallet-1/0x236ba53B56FEE4901cdac3170D17f827DF43E969"
           polygon:
             - "laptop:wallet-2/0xEad0B2b6f6ab84d527569835cd7fe364e067cFFf"
+          arbitrum:
+            - "phone:wallet-2/0xd3b29C94a67Cfa949FeD7dd1474B71d006fa0A2A"
+          base:
+            - "laptop:wallet-3/0x4C7219b760b71B9415E0e01Abd34d0f65631e57e"
+          optimism:
+            - "phone:wallet-3/0x53004E863Aa0F4028B154ECA65CFb32Eb5a8f5bB"
 
       ledger:
-        # API scanner keys can be generated at etherscan.io, polygonscan.com
-        # key format: blockchain1/API_KEY1,blockchain2/API_KEY2
-        key: "ethereum/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+        key: "etherscan/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
         subaccount:
           algorand:
             - "nano:x-1:general-1/R7U6QWS4QLDB5YLBI25TWCPW47N565FUUDP6GG5XEWAKD5INLATHIG24NE"