[Compliance] Store reverse charge status

[fthobe]

Concerns (but doesn't solve): #6112 #6110

Summary

This is the first in a series of PRs to achieve fiscal compliance with EU regulation on Solidus easier.
This dropdown, which will also be introduced on Addresses in the future allows to set a Store as reverse charge compliant, allowing to decide on a per store front level if reverse charge can be applied.

This can be especially useful if driving different stores with different legal entities.

Checklist

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[fthobe]

@shahmayur001 We need to add the OpenAPI docs for this one.

[fthobe]

@kennyadsl should be ok, only test failing is store credit being flaky on admin

[fthobe]

@tvdeyen @kennyadsl Failing test doesn't seem to be related, can we merge this? It's a preparatory step for fixing the vat discussion and allows to either manually or via API determine reverse charge status when we also integrate the organisation fields from PR #6113 down the road.