This PR adds functionality to skip around ANSI escape sequences in catch_textflow so they do not contribute to line length and line wrapping code does not split escape sequences in the middle. I've implemented this by creating a AnsiSkippingString abstraction that has a bidirectional iterator that can skip around escape sequences while iterating. Additionally I refactored Column::const_iterator to be iterator-based rather than index-based so this abstraction is a simple drop-in for std::string.

Currently only color sequences are handled, other escape sequences are left unaffected.

Motivation: Text with ANSI color sequences gets messed up when being output by Catch2 #2833.

Closes #2854

`max_digits10` is the number of decimal digits that the type _can_
represent, in other words, the number of decimal digits needed to
disambiguate any two floating point numbers when serialized to
a string.

Closes #1210

When a signal is caught, the destructors of Sections will not be called.
Thus, we must call `sectionEndedEarly` manually for those Sections.

Example test case:
```
TEST_CASE("broken") {
   SECTION("section") {
      /// Use illegal cpu instruction
      __asm__ __volatile__("ud2" : : : "memory");
   }
}
```

This PR primarily accomplishes two tasks:

1) It adds MODULE.bazel.lock to the .gitignore file.
2) It includes a Bazel build rule for SelfTest, which can be utilized with the command bazel test //tests:catch2_self_test.

The "Catch2 without default main" target is currently unspecified in
Conan, and defaults to catch2::catch2base. This commit switches it back
to Catch2::Catch2, as specified in the docs.

Remove `#pragma intrinsic(_umul128)` because it doesn't work on
ARM64EC and x64 works without it.

Co-authored-by: Agoston Szepessy <agos@microsoft.com>