Add perimeter factory for VPCSC stage

[karpok78]

A proposal to allow for the management of VPC-SC perimeters in yaml factory.
Project discovery is extended to multiple perimeters thanks to query filtering.
Also adding support for bridge perimeters
The default behavior with a simple single perimeter remains.

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Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

[ludoo]

This is very nice. Bridge perimeters are going away now that egress policies support sources, so we might drop them entirely from the stage.

Give me some time to mull over these changes. :)

[karpok78]

I forgot to update the schema. I will have a look at it

[juliocc]

This is really cool.

I wonder if the core functionality should go in the vpc-sc module?

[ludoo]

This is really cool.

I wonder if the core functionality should go in the vpc-sc module?

Ah yes, the vpc-sc factories are all at the module level so the new ones should go there too. Great point.

[karpok78]

I guess the project directory could also be passed down to the module.
And so the factory could be implemented in the module itself. I'll have a look at it