Fix XCom edit modal value not repopulating on reopen.

[Arbaaz123676]

Summary

This PR fixes an issue where the XCom value was not displayed when reopening the edit modal after updating it.

Root Cause

The modal lifecycle and query behavior caused stale or skipped state updates when reopening the modal, leading to an empty value field.

Changes

• Removed lazyMount from the dialog to ensure proper unmount/remount behavior.
• Enabled refetch on mount for the XCom entry query.
• Adjusted the population effect to rely on data instead of data?.value !== undefined.
• Ensured query invalidation for both GetXcomEntries and GetXcomEntry after update.

Result

The XCom edit modal now consistently repopulates the latest value when reopened.

Fixes #61486