* tools: Add unparam linter
unparam detects unused parameters in functions, and a parameter to
a function which only ever takes on one value. The latter is an
indication that more tests are required.
There are many nolints in this PR, as I believe that writing tests
to fix alot of these situations is out of scope for this PR / it
will be changed in future commits. There are some nolints for
when we have to comply to normal api's.
* crypto/keys no longer used by x/gov/client/rest/rest.go
097dd8a164