Implement Helix Support (WIP) (#19175)

Closes #4642 

- Added the ability to switch to helix normal mode, with an additional
helix visual mode.
- <kbd>ctrl</kbd><kbd>h</kbd> from Insert mode goes to Helix Normal
mode. <kbd> i </kbd> and <kbd> a </kbd> to go back.
- Need to find a way to perform the helix normal mode selection with
<kbd> w </kbd>, <kbd>e </kbd>, <kbd> b </kbd> as a first step. Need to
figure out how the mode will interoperate with the VIM mode as the new
additions are in the same crate.

crates/language/src/buffer.rs

@@ -4632,7 +4632,7 @@ impl CharClassifier {
         self.kind(c) == CharKind::Punctuation
     }
 
-    pub fn kind(&self, c: char) -> CharKind {
+    pub fn kind_with(&self, c: char, ignore_punctuation: bool) -> CharKind {
         if c.is_whitespace() {
             return CharKind::Whitespace;
         } else if c.is_alphanumeric() || c == '_' {
@@ -4642,7 +4642,7 @@ impl CharClassifier {
         if let Some(scope) = &self.scope {
             if let Some(characters) = scope.word_characters() {
                 if characters.contains(&c) {
-                    if c == '-' && !self.for_completion && !self.ignore_punctuation {
+                    if c == '-' && !self.for_completion && !ignore_punctuation {
                         return CharKind::Punctuation;
                     }
                     return CharKind::Word;
@@ -4650,12 +4650,16 @@ impl CharClassifier {
             }
         }
 
-        if self.ignore_punctuation {
+        if ignore_punctuation {
             CharKind::Word
         } else {
             CharKind::Punctuation
         }
     }
+
+    pub fn kind(&self, c: char) -> CharKind {
+        self.kind_with(c, self.ignore_punctuation)
+    }
 }
 
 /// Find all of the ranges of whitespace that occur at the ends of lines