file_icons: Use separate keys for C#, Cue, GitLab YAML, Luau, and Solidity (#24711)

This PR updates the file icon mappings such that:

- C# (`.cs`) files map to the `csharp` key
- Cue (`.cue`) files map to the `cue` key
- GitLab YAML (`gitlab-ci.yml`) files map to the `gitlab` key
- Luau (`.luau`) files map to the `luau` key
- Solidity (`.sol`) files map to the `solidity` key

Release Notes:

- Icon themes: Added the ability to change the file icon for C# (`.cs`)
files.
- Icon themes: Added the ability to change the file icon for Cue
(`.cue`) files.
- Icon themes: Added the ability to change the file icon for GitLab YAML
(`gitlab-ci.yml`) files.
- Icon themes: Added the ability to change the file icon for Luau
(`.luau`) files.
- Icon themes: Added the ability to change the file icon for Solidity
(`.sol`) files.

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

assets/icons/file_icons/file_types.json

@@ -27,11 +27,13 @@
     "coffee": "coffeescript",
     "conf": "settings",
     "cpp": "cpp",
+    "cs": "csharp",
     "css": "css",
     "csv": "storage",
     "cxx": "cpp",
     "cts": "typescript",
     "ctsx": "react",
+    "cue": "cue",
     "dart": "dart",
     "dat": "storage",
     "db": "storage",
@@ -66,6 +68,7 @@
     "gitattributes": "vcs",
     "gitignore": "vcs",
     "gitkeep": "vcs",
+    "gitlab-ci.yml": "gitlab",
     "gitmodules": "vcs",
     "TAG_EDITMSG": "vcs",
     "MERGE_MSG": "vcs",
@@ -113,6 +116,7 @@
     "lockb": "bun",
     "log": "log",
     "lua": "lua",
+    "luau": "luau",
     "m4a": "audio",
     "m4v": "video",
     "markdown": "markdown",
@@ -188,6 +192,7 @@
     "scss": "sass",
     "sdf": "storage",
     "sh": "terminal",
+    "sol": "solidity",
     "sql": "storage",
     "sqlite": "storage",
     "stylelint.config.cjs": "stylelint",