keymap: Update Prev to Previous for consistency (#25909)

Closes #10167

This is take 2 on https://github.com/zed-industries/zed/pull/2341 which
was closed due to lack of migrator.

This PR contains rename of following keymap actions: 
```sh
1. ["editor::GoToPrevHunk", { "center_cursor": true }] -> ["editor::GoToPreviousHunk", { "center_cursor": true }]
2. "editor::GoToPrevDiagnostic" -> "editor::GoToPreviousDiagnostic"
3. "editor::ContextMenuPrev" -> "editor::ContextMenuPrevious"
4. "search::SelectPrevMatch" -> "search::SelectPreviousMatch"
5. "file_finder::SelectPrev" -> "file_finder::SelectPrevious"
6. "menu::SelectPrev" -> "menu::SelectPrevious"
7. "editor::TabPrev" -> "editor::Backtab"
```

Release Notes:

- Renamed several keymap actions for consistency (e.g., `GoToPrevHunk` →
`GoToPreviousHunk`, `TabPrev` → `Backtab`). Your existing configured
keybindings will still work. You can click **"Backup and Update"** at
the top of your keymap file to easily update to the new actions.


Co-authored-by: Joseph T. Lyons <JosephTLyons@gmail.com>

assets/keymaps/linux/sublime_text.json

@@ -44,7 +44,7 @@
       "shift-f12": "editor::FindAllReferences",
       "ctrl-shift-f12": "editor::FindAllReferences",
       "ctrl-.": ["editor::GoToHunk", { "center_cursor": true }],
-      "ctrl-,": ["editor::GoToPrevHunk", { "center_cursor": true }],
+      "ctrl-,": ["editor::GoToPreviousHunk", { "center_cursor": true }],
       "ctrl-k ctrl-u": "editor::ConvertToUpperCase",
       "ctrl-k ctrl-l": "editor::ConvertToLowerCase",
       "shift-alt-m": "markdown::OpenPreviewToTheSide",
@@ -62,7 +62,7 @@
     "context": "Pane",
     "bindings": {
       "f4": "search::SelectNextMatch",
-      "shift-f4": "search::SelectPrevMatch",
+      "shift-f4": "search::SelectPreviousMatch",
       "alt-1": ["pane::ActivateItem", 0],
       "alt-2": ["pane::ActivateItem", 1],
       "alt-3": ["pane::ActivateItem", 2],