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>

crates/editor/src/actions.rs

@@ -205,7 +205,7 @@ pub struct GoToHunk {
 
 #[derive(PartialEq, Clone, Deserialize, Default, JsonSchema)]
 #[serde(deny_unknown_fields)]
-pub struct GoToPrevHunk {
+pub struct GoToPreviousHunk {
     #[serde(default)]
     pub center_cursor: bool,
 }
@@ -241,7 +241,7 @@ impl_actions!(
         ExpandExcerptsUp,
         FoldAt,
         GoToHunk,
-        GoToPrevHunk,
+        GoToPreviousHunk,
         HandleInput,
         MoveDownByLines,
         MovePageDown,
@@ -281,7 +281,7 @@ gpui::actions!(
         ContextMenuFirst,
         ContextMenuLast,
         ContextMenuNext,
-        ContextMenuPrev,
+        ContextMenuPrevious,
         ConvertToKebabCase,
         ConvertToLowerCamelCase,
         ConvertToLowerCase,
@@ -325,7 +325,7 @@ gpui::actions!(
         GoToDiagnostic,
         GoToImplementation,
         GoToImplementationSplit,
-        GoToPrevDiagnostic,
+        GoToPreviousDiagnostic,
         GoToTypeDefinition,
         GoToTypeDefinitionSplit,
         HalfPageDown,
@@ -420,7 +420,7 @@ gpui::actions!(
         SplitSelectionIntoLines,
         SwitchSourceHeader,
         Tab,
-        TabPrev,
+        Backtab,
         ToggleAutoSignatureHelp,
         ToggleGitBlame,
         ToggleGitBlameInline,