Consolidated icon definitions

[maffkipp]

Description

• We had multiple identical lists of icon definitions spread across a few different files, this change consolidates them down to one icons.ts file in the shared UI library.

Motivation and Context

• Prevents icons in different parts of the app from potentially getting out of sync with each other

How Has This Been Tested?

• Ensured icons still display in each graph and in various other menus

Screenshots (if appropriate):

Types of changes

• Chore (a change that does not modify the application functionality)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Documentation updates are needed, and have been made accordingly.
• I have added and/or updated tests to cover my changes.
• All new and existing tests passed.
• My changes include a database migration.