Convert luaS functions to TString methods #128

Job	Run time
Sanitizer Tests (ASAN + UBSAN)	38s
Performance Regression Check	1m 25s
Code Quality Checks	58s
Build & Test (gcc-13, Release)	54s
Build & Test (clang-15, Release)	35s
Build & Test (gcc-13, Debug)	56s
Build & Test (clang-15, Debug)	40s
Build Summary	2s
	6m 8s

Provide feedback