[Cloud Security] Add custom column naming support to the UnifiedDataTable component.

[animehart]

Describe the feature:

This is a follow up ticket from comments made on this PR (#183789)
Due to the change we made on the said PR, tables won't have the custom naming by default anymore as the UnifiedDataTable does not support custom column naming.

We should add custom column naming support (Independent from the DataView) to the UnifiedDataTable component.

Definition of Done:

• Create a Custom Column Naming support for the UnifiedDataTable component
• Make sure the FTRs still works

How to Test:
Pre-req: Need Findings data

• Create User with read only permissions
• Login with that User and then navigate to Findings page
• User should be able to see Findings table with no problem

[elasticmachine]

Pinging @elastic/kibana-cloud-security-posture (Team:Cloud Security)

[amirbenun]

Trying to verify as part of QA:

1. Creating a new user with "viewer" role
   

2. findings page is stuck on "loading results" state