Support both celestia and mock (default) for sov-rollup-starter

[dubbelosix]

Summary

Currently sov-rollup-starter is only buit with support for mock. This PR adds support for celestia-da. It uses feature flags so the starter can be built with either celestia or mock (as opposed to being built with both and using runtime flags).

Changes

• docker structure imported from sovereign
• docker related steps from sovereign repo added to make file
• feature flags for building StarterRollup with either celestia-da or mock-da
• Readme modified with a second section for Celestia support. Original section is intact to let new developers build easily with mock
• test-data, config, genesis imported from sovereign as well

Remaining work

It would be ideal to have the docker related files and code not duplicated between sovereign-sdk and sov-rollup-starter. This work will be merged into separating the DA adapters into their own repos (since the general structure is similar - make them git submodules (or subprepos) and then reuse them in sovereign and sov-rollup-starter

[bkolad]

Let's also test the Celestia rollup it CI (in a separate PR)