feat(cache): redis cache (#8822)

# Which Problems Are Solved

Add a cache implementation using Redis single mode. This does not add
support for Redis Cluster or sentinel.

# How the Problems Are Solved

Added the `internal/cache/redis` package. All operations occur
atomically, including setting of secondary indexes, using LUA scripts
where needed.

The [`miniredis`](https://github.com/alicebob/miniredis) package is used
to run unit tests.

# Additional Changes

- Move connector code to `internal/cache/connector/...` and remove
duplicate code from `query` and `command` packages.
- Fix a missed invalidation on the restrictions projection

# Additional Context

Closes #8130

internal/cache/connector/pg/delete.sql

@@ -0,0 +1,5 @@
+delete from cache.string_keys k
+where k.cache_name = $1
+	and k.index_id = $2
+	and k.index_key = any($3)
+;