feat: add new group members endpoint with filtering and pagination (#23067)

Partially addresses #21813 (still need to make changes to the "add user"
button to be complete)

Since there are a lot of user tests already, I moved them into
`coderdtest` to be shared.

coderd/database/queries/groupmembers.sql

@@ -17,6 +17,110 @@ WHERE group_id = @group_id
         user_is_system = false
       END;
 
+-- name: GetGroupMembersByGroupIDPaginated :many
+SELECT
+	*, COUNT(*) OVER() AS count
+FROM
+	group_members_expanded
+WHERE
+	group_members_expanded.group_id = @group_id
+	AND CASE
+		-- This allows using the last element on a page as effectively a cursor.
+		-- This is an important option for scripts that need to paginate without
+		-- duplicating or missing data.
+		WHEN @after_id :: uuid != '00000000-0000-0000-0000-000000000000'::uuid THEN (
+			-- The pagination cursor is the last ID of the previous page.
+			-- The query is ordered by the username field, so select all
+			-- rows after the cursor.
+			(LOWER(user_username)) > (
+				SELECT
+					LOWER(user_username)
+				FROM
+					group_members_expanded
+				WHERE
+					group_id = @group_id
+					AND user_id = @after_id
+			)
+		)
+		ELSE true
+	END
+	-- Start filters
+	-- Filter by email or username
+	AND CASE
+		WHEN @search :: text != '' THEN (
+			user_email ILIKE concat('%', @search, '%')
+			OR user_username ILIKE concat('%', @search, '%')
+		)
+		ELSE true
+	END
+	-- Filter by name (display name)
+	AND CASE
+		WHEN @name :: text != '' THEN
+			user_name ILIKE concat('%', @name, '%')
+		ELSE true
+	END
+	-- Filter by status
+	AND CASE
+		-- @status needs to be a text because it can be empty, If it was
+		-- user_status enum, it would not.
+		WHEN cardinality(@status :: user_status[]) > 0 THEN
+			user_status = ANY(@status :: user_status[])
+		ELSE true
+	END
+	-- Filter by rbac_roles
+	AND CASE
+		-- @rbac_role allows filtering by rbac roles. If 'member' is included, show everyone, as
+		-- everyone is a member.
+		WHEN cardinality(@rbac_role :: text[]) > 0 AND 'member' != ANY(@rbac_role :: text[]) THEN
+			user_rbac_roles && @rbac_role :: text[]
+		ELSE true
+	END
+	-- Filter by last_seen
+	AND CASE
+		WHEN @last_seen_before :: timestamp with time zone != '0001-01-01 00:00:00Z' THEN
+			user_last_seen_at <= @last_seen_before
+		ELSE true
+	END
+	AND CASE
+		WHEN @last_seen_after :: timestamp with time zone != '0001-01-01 00:00:00Z' THEN
+			user_last_seen_at >= @last_seen_after
+		ELSE true
+	END
+	-- Filter by created_at
+	AND CASE
+		WHEN @created_before :: timestamp with time zone != '0001-01-01 00:00:00Z' THEN
+			user_created_at <= @created_before
+		ELSE true
+	END
+	AND CASE
+		WHEN @created_after :: timestamp with time zone != '0001-01-01 00:00:00Z' THEN
+			user_created_at >= @created_after
+		ELSE true
+	END
+	 -- Filter by system type
+	AND CASE
+		WHEN @include_system::bool THEN TRUE
+		ELSE user_is_system = false
+	END
+	AND CASE
+		WHEN @github_com_user_id :: bigint != 0 THEN
+			user_github_com_user_id = @github_com_user_id
+		ELSE true
+	END
+	-- Filter by login_type
+	AND CASE
+		WHEN cardinality(@login_type :: login_type[]) > 0 THEN
+			user_login_type = ANY(@login_type :: login_type[])
+		ELSE true
+	END
+	-- End of filters
+ORDER BY
+	-- Deterministic and consistent ordering of all users. This is to ensure consistent pagination.
+	LOWER(user_username) ASC OFFSET @offset_opt
+LIMIT
+	-- A null limit means "no limit", so 0 means return all
+	NULLIF(@limit_opt :: int, 0);
+
 -- name: GetGroupMembersCountByGroupID :one
 -- Returns the total count of members in a group. Shows the total
 -- count even if the caller does not have read access to ResourceGroupMember.