Move SystemUpdater to top level settings and make it searchable

Description

This MR is intended to move system updater settings to top and make it searchable.

Related issues

e/backlog#2241 (closed)

This MR also fixes this closed issue -> e/backlog#1076 (closed), e/backlog#1076 (comment 67990) e/backlog#2224 (closed)

Type of change

• 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 not work as expected)
• This change requires a documentation update

Related MRs

How has this been tested?

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules