container: bash: add plugins support / lib_plugins

- Executes plugins within profile/subprofile context
  * Hooks into the container's global environment

container/src/finance/finance.bash

@@ -58,6 +58,7 @@ function main()
   ledger-ui     \e[34;3mStart terminal UI (hledger-ui)\e[0m
   ledger-web    \e[34;3mStart web-based UI (hledger-web)\e[0m
   meta          \e[34;3mSearch local financial metadata\e[0m
+  plugins       \e[34;3mExecute given plugin available in plugins' path\e[0m
   reports       \e[34;3mGenerate balance sheet, income statement, etc.\e[0m
   root          \e[34;3mRun ROOT.cern instance for docker-finance analysis\e[0m
   taxes         \e[34;3mGenerate tax reports\e[0m
@@ -122,6 +123,9 @@ function main()
     meta)
       lib_finance::meta "${@:3}"
       ;;
+    plugins)
+      lib_finance::plugins "${@:3}"
+      ;;
     reports)
       lib_finance::reports "${@:3}"
       ;;