string_methods: Add includes(), trimStart(), and trimEnd()

Update CMake system

Remove Biicode Support

ChaiScript 6+ changed the vector_type signature from returning a ModulePtr
to taking a Module& parameter and returning void. The ChaiScript constructor
also no longer accepts a ModulePtr for stdlib. Updated bootstrap() to register
the vector_type for std::vector<std::string> directly within the module, and
updated tests to use the new ChaiScript 6+ API. Fixed Catch SIGSTKSZ
compile error on newer glibc where SIGSTKSZ is no longer a constant expression.

Co-authored-by: leftibot <leftibot@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Adds a CI workflow modeled on ChaiScript/ChaiScript's pattern: build and
test across Linux (GCC), macOS (AppleClang), and Windows (MSVC) in both
Debug and Release, plus ASAN+UBSAN sanitizer jobs on Linux and macOS.
The workflow reuses the project's existing CMake options
(ENABLE_ADDRESS_SANITIZER, ENABLE_UNDEFINED_SANITIZER), so no build-system
changes are required.

Co-authored-by: leftibot <leftibot@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>