Add Company Name to Permission Set In Plan buffer

[stkillen]

What & why

Add Company Name to Permission Set In Plan Buffer.

Currently, when defining custom permission sets for a plan you can only add one per company, since company is not part of the PK.

Linked work

Fixes AB#620304

How I validated this

• I read the full diff and it contains only changes I intended.
• I built the affected app(s) locally with no new analyzer warnings.
• I ran the change in Business Central and confirmed it behaves as expected.
• I added or updated tests for the new behavior, or explained below why none are needed.

What I tested and the outcome (required — be specific: scenarios, commands, screenshots for UI changes)

Risk & compatibility