[CDEC-418] Reunite orphan Bi instances in txp

[intricate]

Description

This PR reunites orphan Bi instances from txp/src/Pos/Txp/Binary* with their type definitions.

Notes

It turned out that moving the Bi instance for (DataMsg TxMsgContents) was a lot more involved than I had anticipated.

Since DataMsg is a type defined in infra rather than txp, I decided that the Bi instance was best suited to be in infra. However, if I were to do this, infra would then have to depend upon txp since TxMsgContents is a type defined in Pos.Txp.Network.Types. This would introduce a circular dependency since txp already depends upon infra.

As a result of this, I ended up moving TxMsgContents from txp to infra.

I also moved all of the Arbitrary instances from Test.Pos.Txp.Arbitrary (txp-test) to Test.Pos.Core.Arbitrary.Txp (core-test) since they were all instances of core types anyways.

Linked issue

https://iohk.myjetbrains.com/youtrack/issue/CDEC-418

Type of change

• 🐞 Bug fix (non-breaking change which fixes an issue)
• 🛠 New feature (non-breaking change which adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)
• 🏭 Refactoring that does not change existing functionality but does improve things like code readability, structure etc
• 🔨 New or improved tests for existing code
• ⛑ git-flow chore (backport, hotfix, etc)

Developer checklist

• I have read the style guide document, and my code follows the code style of this project.
• If my code deals with exceptions, it follows the guidelines.
• I have updated any documentation accordingly, if needed. Documentation changes can be reflected in opening a PR on cardanodocs.com, amending the inline Haddock comments, any relevant README file or one of the document listed in the docs directory.

Testing checklist

• I have added tests to cover my changes.
• All new and existing tests passed.

QA Steps

Screenshots (if available)

[Jimbo4350]

Shouldn't this be in txp/src/Pos/Txp/Network/Types.hs with TxMsgContents as per: https://iohk.myjetbrains.com/youtrack/issue/CDEC-401 @erikd

[erikd]

Normally probably yes, and in the end, maybe yes, but right now, definitely no :).

What we are aiming for at the moment is to fix txp so it no longer depends in infra and in the end, make infra depend on txp. We also want to avoid doing this in one huge PR that takes a week or more to get ready and then days to review etc.

So, we are temporarily going to contravene our normal good practices and do what ever it takes to fix the way txp and infra depend on each other.

[Jimbo4350]

Waiting on Erik's feedback

[erikd]

Looks good to me. Needs a rebase and would be good to fix the stylish haskell wibbles along the way.

[Jimbo4350]

LGTM!

[erikd]

I'm going to merge this as soon as it passes CI :)