Game flow rework (pt 5)

[rr-]

Checklist

• I have read the coding conventions
• I have added a changelog entry about what my pull request accomplishes, or it is an internal change
• I have added a readme entry about my new feature or OG bug fix, or it is a different change

Description

• Chiefly, this PR tries to somehow tame the split of the level arrays in TR2. TR1 still uses a linear array.
• Makes g_CurrentLevel a pointer to GAME_FLOW_LEVEL (TR2 only)
• Changes GF_GetLevelCount() signature to accept GAME_FLOW_LEVEL_TYPE
• Introduces GAME_FLOW_LEVEL *GF_GetLevel(int32_t num, GAME_FLOW_LEVEL_TYPE level_type)
• Moves MUSIC_TRACK to libtrx
• Merges common game flow types in libtrx
• Adds ability for game string tables to define demos and cutscene specific strings (TR2 only)
• Fixes TR2 /pos returning weird names in demos and cutscenes

[github-actions]

Download the built assets for this pull request:

• TR1X-4.7.1-613-gff28fbd-linux.zip
• TR1X-4.7.1-613-gff28fbd-mac.zip
• TR1X-4.7.1-613-gff28fbd-win.zip
• TR1X-4.7.1-613-gff28fbd-win-installer.zip
• TR2X-0.8-391-gff28fbd-linux.zip
• TR2X-0.8-391-gff28fbd-win.zip

[aredfan]

TR2X crashes when cutscenes finishes or gets skipped, for example:

1. /play 1
2. use the level skip cheat
3. skip the cutscene

[lahm86]

Lara's Home appears in the title screen in TRUB if you play a level and then return to the title screen - I admit I didn't check this in the last PR and it looks like it's happening there too, I can raise an issue if you prefer as it's not directly related to this one.

[rr-]

Lara's Home appears in the title screen in TRUB if you play a level and then return to the title screen - I admit I didn't check this in the last PR and it looks like it's happening there too, I can raise an issue if you prefer as it's not directly related to this one.

I'll tackle this here, as it's a regression in develop only.
Edit: broken here – 717e045 inv-ring: create INV_RING_SOURCE

[rr-]

@aredfan @lahm86 this is now ready for a re-review.