FileFormats/CHK: save is incorrect and round-trip inconsistent

[myocytebd]

• A few minor bugs on CHK save;
• STR section is round-trip inconsistent;
• TRIG/MBRF sections are round-trip inconsistent.

(.txt due to github bug)
0001-FileFormats-CHK-fix-CHK-save-and-add-round-trip-test.patch.txt

• Fix a few minor bugs on CHK save/load.
• Make STR section usually round-trip consistent.
• Add an option to bypass TRIG/MBRF decompilation.
• Add a round-trip test.
  With TRIG/MBRF disabled, most SC:R locales/enUS/Assets/campaign/ chk files are round-trip exact, except locales/enUS/Assets/campaign/EXPTerran/Terran04/staredit/scenario_rev4.chk (STR section has same strings but not byte accurate).

[poiuyqwert]

Hey @myocytebd, thanks for the details. The CHK stuff definitely has the least amount of love put into it since it isnt much called for by modders, and was mostly a fun side thing for me. I would love to get it fixed up and more feature rich, so I am glad to get any input/feadback you have. Thanks!