TBR: playground: Move lib/mysql.go to release.go.lib/dbutil.

Cleanup after https://vanadium-review.googlesource.com/#/c/4374/

Change-Id: I0098e976366aed911bc534304e1296d691da4f72
2 files changed
tree: 514cce8284aa43f83983733c26f50301ff53ec08
  1. client/
  2. go/
  3. pgbundle/
  4. .gitignore