feat: parse interpolated localized strings

[ezhevita]

Resolves #24.

Adds support for parsing localized strings in the following functions:

• c_msgnextsubloc
• c_msgsetsubloc
• msgnextsubloc
• msgsetsubloc

Example (gml_GlobalScript_scr_get_completed_file_name from Deltarune Chapter 4):

The interpolated argument can be hovered over to reveal its index:

In the future it could be made so hovering over displays the interpolated expression itself, but this is beyond the scope of this pull request.

[ezhevita]

I thought about displaying interpolated expressions instead of "Argument №X", but it requires to properly parse the line syntactically in order to extract the arguments (since they might contain nested function calls or strings, so just splitting by , is not enough).

There are at least 2 unique occurrences in Deltarune where this is the case:

• msgsetsubloc(0, "B~1b~2e", random_vowel, choose("i", "l"), "obj_watercooler_enemy_slash_Step_0_gml_38_0"); in chapter 3 gml_Object_obj_watercooler_enemy_Step_0 and chapter 4 gml_Object_obj_holywatercooler_enemy_Step_0
• msgsetsubloc(0, "~1&* (Drink Name: ~2.)/", juice_text, scr_juice_name(yellow_amount, red_amount), "scr_text_slash_scr_text_gml_8950_0"); in chapter 4 gml_GlobalScript_scr_text

[KockaAdmiralac]

Thanks!