Backport of #48849. Update `.editorconfig` to make the Java settings the
default for all files, and then apply a 2-space indent to all `*.gradle`
files. Then reformat all the files.
Moves `x-pack/qa/sql/*` into `x-pack/plugin/sql/qa` to make it simpler
to run all of the sql tests. This lines up with how newer projects like
cross cluster replication are testing themselves.