Admin: stub out override and pausing methods for dry-run

[aarongable]

Dry run stubs for the SA's override and pausing methods were not added when this functionality was added to the admin tool. This means that attempts to run these subcommands in dry-run mode result in nil pointer exceptions when it tries to call unimplemented methods on the dryRunSAC.

Fixes #8577

[jsha]

Comparing to #8588, this could use an implements assertion for dryRunSAC:

var _ rapb.StorageAuthorityClient = (*dryRunSAC)(nil)

[aarongable]

Comparing to #8588, this could use an implements assertion for dryRunSAC:

var _ rapb.StorageAuthorityClient = (*dryRunSAC)(nil)

It could, but it doesn't accomplish anything. The dryRunSAC struct embeds the rapb.StorageAuthorityClient interface, so it trivially implements the interface despite some of those "implementations" being nil pointers:

boulder/cmd/admin/dryrun.go

Lines 29 to 30 in 534c06a

	type dryRunSAC struct {
	sapb.StorageAuthorityClient

The interface assertion would be valuable if we removed that embedding, but then we'd have to actually stub out all the other methods in the StorageAuthorityClient interface, too.

[jsha]

Perhaps, then, admin.go should define its own interface that is the subset of SA methods it uses? Then dryRunSAC could remove the embedding and still implement the interface that admin.go needs. That would allow us to catch future instances of this mistake at compile time.

[aarongable]

Yeah that makes sense. I've added stripped down interfaces that are re-implemented by the dryrun structs.