Make word deletions less greedy (#37352)

Closes https://github.com/zed-industries/zed/issues/37144

Adjusts `editor::DeleteToPreviousWordStart`,
`editor::DeleteToNextWordEnd`, `editor::DeleteToNextSubwordEnd` and
`editor::DeleteToPreviousSubwordStart` actions to

* take whitespace sequences with length >= 2 into account and stop after
removing them (whilst movement would also include the word after such
sequences)

* take current language's brackets into account and stop after removing
the text before them

The latter is configurable and can be disabled with `"ignore_brackets":
true` parameter in the action.

Release Notes:

- Improved word deletions to consider whitespace sequences and brackets
by default

assets/keymaps/default-linux.json

@@ -63,8 +63,8 @@
       "ctrl-k": "editor::CutToEndOfLine",
       "ctrl-k ctrl-q": "editor::Rewrap",
       "ctrl-k q": "editor::Rewrap",
-      "ctrl-backspace": "editor::DeleteToPreviousWordStart",
-      "ctrl-delete": "editor::DeleteToNextWordEnd",
+      "ctrl-backspace": ["editor::DeleteToPreviousWordStart", { "ignore_newlines": false, "ignore_brackets": false }],
+      "ctrl-delete": ["editor::DeleteToNextWordEnd", { "ignore_newlines": false, "ignore_brackets": false }],
       "cut": "editor::Cut",
       "shift-delete": "editor::Cut",
       "ctrl-x": "editor::Cut",