In this commit, we add additional make commands to run optional itests,
where specific test cases are still specified with the 'icase' variable.
Additional optional itests are added in the same way as default itests.
We also remove the old-style build tags that were replaced with Go 1.17.

In this commit, we update the logic used in all itests to mint assets
to reduce the number of RPC calls made and total time spent on asserts.
We also separate waiting for the planter to change state and checking
the daemon state.

Because the String() function just returns the hash of the ID, it is
hard to debug whether both the asset ID and group key are set during
universe sync. This commit adds a bit more information to certain log
lines.

In this commit, we add a test that mints a large batch of collectibles
with large metadata, and then checks that the batch mint succeeded.
This includes correctly updating the universe server of the minting
node, and syncing that universe tree to a second node.

If SQLITE_BUSY is returned, it means waiting for a transaction failed
because too many other readers/writers are currently using the DB. We
can detect that error, convert it into a serialization error and detect
that in the existing retry loop.
We also re-try if creating or committing a transaction fails with a
serialization error.