multi: move breach arbiter and utxo nursery into contractcourt package

In this commit, we take an initial step towards converting the existing
breach arbiter and utxo nursery logic into contract resolvers by moving
the files as is, into the `contractcourt` pacakge.

This commit is primarily move only, though we had to massage some
interfaces and config names along the way to make things compile and the
tests run properly.

docs/release-notes/release-notes-0.14.0.md

@@ -229,6 +229,8 @@ you.
 
 * [Refactor the interaction between the `htlcswitch` and `peer` packages for cleaner separation.](https://github.com/lightningnetwork/lnd/pull/5603)
 
+* [Moved the original breach handling and timelock UTXO handling into the contract court package](https://github.com/lightningnetwork/lnd/pull/5745)
+
 * [Unused error check 
   removed](https://github.com/lightningnetwork/lnd/pull/5537).