feat : Add global search result navigation shortcuts

[NikkiAung]

Add global search result navigation shortcuts #3240

Add ALT+. and ALT+, shortcuts for navigating search results globally
without requiring manual Search view switching. This improves workflow
efficiency when reviewing and editing multiple search result occurrences.

Fixes #3240

ALT+. Flow (Next Search Entry)

User presses ALT+.
    ↓
plugin.xml: "ALT+. triggers globalNextSearchEntry command"
    ↓
plugin.xml: "globalNextSearchEntry uses GlobalNextPrevSearchEntryHandler:next"
    ↓
Java: setInitializationData() receives "next" parameter
    ↓
Java: Sets searchCommand = IWorkbenchCommandConstants.NAVIGATE_NEXT
    ↓
Java: execute() method runs three-command sequence:
    1. Show Search view
    2. Execute NAVIGATE_NEXT command
    3. Activate editor

ALT+, Flow (Previous Search Entry)

User presses ALT+,
    ↓
plugin.xml: "ALT+, triggers globalPreviousSearchEntry command"
    ↓
plugin.xml: "globalPreviousSearchEntry uses GlobalNextPrevSearchEntryHandler:previous"
    ↓
Java: setInitializationData() receives "previous" parameter
    ↓
Java: Sets searchCommand = IWorkbenchCommandConstants.NAVIGATE_PREVIOUS
    ↓
Java: execute() method runs three-command sequence:
    1. Show Search view
    2. Execute NAVIGATE_PREVIOUS command
    3. Activate editor