feat(ParticipantStore): add SQL store

[wolf4ood]

What this PR changes/adds

Add SQL store implementation for ParticipantStore

Why it does that

Durability of participants and scalability for the Registration service

Linked Issue(s)

Closes #41

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• added relevant details to the changelog? (skip with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and styleguide for details)

[bscholtes1A]

I am a bit concerned about pulling dependencies on other extensions and on test libraries into the *-spi directory. But maybe it's acceptable if it's only test fixture implementations... @paullatzelsperger what do you think?

[wolf4ood]

@bscholtes1A the deps to authority-spi can be easily removed since it's only one fixture. But since the model is there it made sense to use that module fixtures

The test engine it's needed. We did the same thing on the other stores by providing a base test for all the store implementation like here
https://github.com/eclipse-dataspaceconnector/DataSpaceConnector/blob/main/spi/control-plane/contract-spi/build.gradle.kts#L31

[paullatzelsperger]

@bscholtes1A @wolf4ood I would slightly lean toward ben's position, i.e. removing the dependency onto dataspace-authority-spi, because we're only using a simple factory method, but I don't think this is a big issue either way.