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/get.sql

@@ -0,0 +1,19 @@
+update cache.objects
+set last_used_at = now()
+where cache_name = $1
+	and	(
+		select object_id
+		from cache.string_keys k
+		where cache_name = $1
+			and index_id = $2
+			and index_key = $3
+		) = id
+	and case when $4::interval > '0s'
+		then created_at > now()-$4::interval -- max age
+		else true
+	end
+	and case when $5::interval > '0s'
+		then last_used_at > now()-$5::interval -- last use
+		else true
+	end
+returning payload;