There are nine reporters in Catch2 3.5.2, Automake, compact, console,
JSON, JUnit, SonarQube, TAP, TeamCity and XML.

This means that the CLI interface now uses the new key-value oriented
reporter spec, the common reporter base creates the colour implementation
based on the reporter-specific configuration, and it also stores the
custom configuration options for each reporter instance.

Closes #339 as it allows per-reporter forcing of ansi colour codes.

This is useful as a centralized place for handling common reporter
problems like handling output streams, and soon also colour impl
handling.

Closes #2259

This requires a bunch of different changes across the reporter
subsystem.

* We need to handle multiple reporters and their differing
  preferences in `ListeningReporter`, e.g. what to do when
  we mix reporters that capture and don't capture stdout.
* We need to change how the reporter is given output and
  how we parse reporter's output destination from CLI.
* Approval tests need to handle multireporter option

It outputs reports in the `Generic Execution Test Data` format, see
https://docs.sonarqube.org/latest/analysis/generic-test/, specifically
https://docs.sonarqube.org/latest/analysis/generic-test/#header-2

Close #1738 (this is a cherry-pick and fixup of that PR)

Prevent warnings
- gnu: -Wcomment: multi-line comment
- clang: -Wweak-vtables 'class' has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit
- clang: -Winconsistent-missing-override: 'method' overrides a member function but is not marked 'override'
- MSVC: C4702: unreachable code