Refactor code into indexer-common crate

[Jannis]

This moves out much of the common code into an indexer-common crate. The next step is likely to make more clear how one would go about implementing a different kind of indexer service.

[aasseman]

This is awesome, I actually just barely started working on this to share components with the "indexer-tap-agent" (or better name if someone feels inspired)

[Jannis]

@aasseman Ok, I expect this to pass the checks.

I didn't want to move the escrow monitor just yet. To avoid that, I had to split up the test_vectors. I think the TAP manager tests needed the allocation monitor and so I had to add a mock feature to the indexer-common crate to export the faux code generated for it across for testing. Probably something we can clean up again later.

[aasseman]

@aasseman Ok, I expect this to pass the checks.

I didn't want to move the escrow monitor just yet. To avoid that, I had to split up the test_vectors. I think the TAP manager tests needed the allocation monitor and so I had to add a mock feature to the indexer-common crate to export the faux code generated for it across for testing. Probably something we can clean up again later.

I agree on all points. The mocking was what slowed me down considerably in my attempt to split things off into a common crate this weekend. I can take a stab at the EscrowMonitor in particular in another PR. I'm the only one depending on this for now so you don't need to struggle with this.

[aasseman]

LGTM except for 2 small things.
Also I think this should wait for #52 since this branch is based on top of it.

[aasseman]

The merge-base changed after approval.

[Jannis]

Rebased after #52 was merged. Let's see if the tests still pass.

[hopeyen]

could use another bad_request_response?

[Jannis]

Oh, good catch. Fixed!