feat: adds main_comp_only to create_new_with_filter in ssp.py

[jpower432]

Description

The main component is needed in a trestle SSP for it be valid. This has been added by default when filtering by components in workspace component definitions and option added to filter out all component but the main.

Type of change

• New feature (non-breaking change which adds functionality) Not user facing feature

How has this been tested?

• Updated unit tests

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
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[beatrizmcouto]

LGTM