Remove unused services

[Arif-Khalid]

Summary:

Fixes part of #72

Type of change:

• 🎨 Code Refactoring

Changes Made:

• Removed permission.service.ts
• Removed data.service.ts

Proposed Commit Message:

Remove unused services in WATcher.

There are a couple of unused services ported from CATcher.

Unnecessary services contributes to code clutter and hurts understandability
of code base.

Let's remove these unused services from WATcher to increase code cleanliness.

Checklist:

• I have tested my changes thoroughly.
• I have created tests for any new code files created in this PR or provided a link to a issue/PR that addresses this.
• I have added or modified code comments to improve code readability where necessary.
• I have updated the project's documentation as necessary.

[cheehongw]

Seems like the changes in this PR have already been merged in #238, closing this PR