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>

crates/theme/src/icon_theme.rs

@@ -66,7 +66,9 @@ const FILE_ICONS: &[(&str, &str)] = &[
     ("code", "icons/file_icons/code.svg"),
     ("coffeescript", "icons/file_icons/coffeescript.svg"),
     ("cpp", "icons/file_icons/cpp.svg"),
+    ("csharp", "icons/file_icons/file.svg"),
     ("css", "icons/file_icons/css.svg"),
+    ("cue", "icons/file_icons/file.svg"),
     ("dart", "icons/file_icons/dart.svg"),
     ("default", "icons/file_icons/file.svg"),
     ("diff", "icons/file_icons/diff.svg"),
@@ -78,6 +80,7 @@ const FILE_ICONS: &[(&str, &str)] = &[
     ("eslint", "icons/file_icons/eslint.svg"),
     ("font", "icons/file_icons/font.svg"),
     ("fsharp", "icons/file_icons/fsharp.svg"),
+    ("gitlab", "icons/file_icons/settings.svg"),
     ("gleam", "icons/file_icons/gleam.svg"),
     ("go", "icons/file_icons/go.svg"),
     ("graphql", "icons/file_icons/graphql.svg"),
@@ -94,6 +97,7 @@ const FILE_ICONS: &[(&str, &str)] = &[
     ("lock", "icons/file_icons/lock.svg"),
     ("log", "icons/file_icons/info.svg"),
     ("lua", "icons/file_icons/lua.svg"),
+    ("luau", "icons/file_icons/file.svg"),
     ("markdown", "icons/file_icons/book.svg"),
     ("metal", "icons/file_icons/metal.svg"),
     ("nim", "icons/file_icons/nim.svg"),
@@ -112,6 +116,7 @@ const FILE_ICONS: &[(&str, &str)] = &[
     ("sass", "icons/file_icons/sass.svg"),
     ("scala", "icons/file_icons/scala.svg"),
     ("settings", "icons/file_icons/settings.svg"),
+    ("solidity", "icons/file_icons/file.svg"),
     ("storage", "icons/file_icons/database.svg"),
     ("stylelint", "icons/file_icons/javascript.svg"),
     ("svelte", "icons/file_icons/html.svg"),