Fix frametags 1514

[natebot13]

Fixes issue #1514
Utilizes a subset of the string formatting capabilities to format tag names when exporting to json

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[natebot13]

would love to get this reviewed and merged if possible

[dacap]

Hi @natebot13, I'll take a look right now.

[dacap]

Thanks for this @natebot13, it's looks great, I've just merged it 👍 I've fixed some conflict (as we moved ExportSpriteSheetParams to cmd_export_sprite_sheet.h), made some adjustments in the UI (+restoring saved tagname format from previous sessions), e.g.

Before

after

And added a new test. I'll add a new #tagname-format section to the CLI docs right now too.

Thanks again 🙏