This commit simply splits the interfaces but introduces no new structs
- Introduce the QueryPackStore, mrvacommander/pkg/qpstore
- Introduce the CodeQL database store, pkg/qldbstore/interfaces.go
All access is/will be through interfaces accessed through these structs.
This introduces several distinct storage units:
+ DB for server state
+ DB for codeql databases
+ query pack store
The steps for manually creating needed databases are in the README
