Merge bitcoin/bitcoin#22859: Replace uses of boost::trim* with locale-independent alternatives (#18130 rebased)

696c76d660 tests: Add TrimString(...) tests (practicalswift)
4bf18b089e Replace use of boost::trim_right with locale-independent TrimString (Ben Woosley)
93551862a1 Replace use of boost::trim use with locale-independent TrimString (Ben Woosley)

Pull request description:

  This is [#18130 rebased](https://github.com/bitcoin/bitcoin/pull/18130#issuecomment-900158759).

  > `TrimString` is an existing alternative.

  > Note `TrimString` uses `" \f\n\r\t\v"` as the pattern, which is consistent with the default behavior of `std::isspace`. See: https://en.cppreference.com/w/cpp/string/byte/isspace

ACKs for top commit:
  jb55:
    utACK 696c76d660
  practicalswift:
    ACK 696c76d660
  jonatack:
    ACK 696c76d660
  theStack:
    Code-review ACK 696c76d660

Tree-SHA512: 6a70e3777602dfa65a60353e5c6874eb951e4a806844cd4bdaa4237cad980a4f61ec205defc05a29f9707776835975838f6cc635259c42adfe37ceb02ba9358d

test/lint/lint-locale-dependence.sh

@@ -39,10 +39,8 @@ export LC_ALL=C
 
 KNOWN_VIOLATIONS=(
     "src/bitcoin-tx.cpp.*stoul"
-    "src/bitcoin-tx.cpp.*trim_right"
     "src/dbwrapper.cpp.*stoul"
     "src/dbwrapper.cpp:.*vsnprintf"
-    "src/httprpc.cpp.*trim"
     "src/node/blockstorage.cpp:.*atoi"
     "src/qt/rpcconsole.cpp:.*atoi"
     "src/rest.cpp:.*strtol"