Reworks the regexp options to use file globbing instead

Regexp wasn't working for everyone, the exclude option was completely non functional
This commit converts to using the standard glob format for file names
It also tidies up the handling of supported languages in the language server
This will make the old setting searchFileExtensions not work anymore and if anyone had regexps in the exclude they prob will not work going forwards until they are converted

client/package.json

@@ -54,17 +54,17 @@
                     },
                     "description": "A list of vscode language names where the extension should be used."
                 },
-                "css_peek.searchFileExtensions": {
+                "css_peek.include": {
                     "type": "array",
                     "default": [
-                        ".css",
-                        ".scss",
-                        ".less"
+                        "**/*.css",
+                        "**/*.scss",
+                        "**/*.less"
                     ],
                     "items": {
                         "type": "string"
                     },
-                    "description": "A list of extensions that should be tried for finding peeked files."
+                    "description": "A list of file globs to allow peeking into"
                 },
                 "css_peek.exclude": {
                     "type": "array",
@@ -75,7 +75,7 @@
                     "items": {
                         "type": "string"
                     },
-                    "description": "Files are ignored from the CSS lookup if they match any of these Regular Expressions (regex)."
+                    "description": "A list of file globs that filters out peekable files"
                 },
                 "css_peek.trace.server": {
                     "scope": "window",