Add support for pagination with Query API in Redis State Store

[gspadotto]

It seems that the paginated Query API is not being unit tested for Redis as - for example - is done here for Postgresql:

components-contrib/common/component/postgresql/v1/postgresql_query_test.go

Lines 36 to 43 in c693061

	{
	input: "../../../../tests/state/query/q2.json",
	query: "SELECT key, value, xmin as etag FROM state WHERE value->>'state'=$1 LIMIT 2",
	},
	{
	input: "../../../../tests/state/query/q2-token.json",
	query: "SELECT key, value, xmin as etag FROM state WHERE value->>'state'=$1 LIMIT 2 OFFSET 2",
	},

Expected Behavior

Add a unit test that checks that pagination works with Query API on Redis State Store

Actual Behavior

Query API on Redis State store seems not to be working correctly (at least on 1.12.4) when using "limit" and "token" parameters.

Steps to Reproduce the Problem

Try Query API with pagination parameters (token and limit) on a Redis State Store anche check that the correct responses are received.

Release Note

RELEASE NOTE: FIX Pagination management on Query API for Redis.

[berndverst]

Query API is poorly designed and will never become stable, so I don't advise relying on this. It will remain Alpha forever. Some other maintainers didn't agree labeling it as deprecated - but in reality, it's quasi deprecated.

Some features like pagination only works for a subset of the few state stores that implement Query API support. This is expected. From our understanding, Redis has no mechanism that would allow us to implement pagination - and we also do not consider this to be a priority.

EDIT: We use HGET and JSON.GET functions from REDIS which do not support paging. To support paging in Query API properly we would also have to change how Dapr stores data in redis using indices.

One option is to create an index from your search parameters using https://redis.io/commands/ft.create/ and then using https://redis.io/commands/ft.aggregate/ with Cursor to begin the search on that index, and then paging via https://redis.io/commands/ft.cursor-read/

PRs welcome.