chore: merge organization member db queries (#13542)

Merge members queries into 1 that also joins in the user table for username.
Required to list organization members on UI/cli

coderd/database/queries/organizationmembers.sql

@@ -1,13 +1,28 @@
--- name: GetOrganizationMemberByUserID :one
+-- name: OrganizationMembers :many
+-- Arguments are optional with uuid.Nil to ignore.
+--  - Use just 'organization_id' to get all members of an org
+--  - Use just 'user_id' to get all orgs a user is a member of
+--  - Use both to get a specific org member row
 SELECT
-	*
+	sqlc.embed(organization_members),
+	users.username
 FROM
 	organization_members
+		INNER JOIN
+	users ON organization_members.user_id = users.id
 WHERE
-	organization_id = $1
-	AND user_id = $2
-LIMIT
-	1;
+	-- Filter by organization id
+	CASE
+		WHEN @organization_id :: uuid != '00000000-0000-0000-0000-000000000000'::uuid THEN
+			organization_id = @organization_id
+		ELSE true
+	END
+	-- Filter by user id
+	AND CASE
+		WHEN @user_id :: uuid != '00000000-0000-0000-0000-000000000000'::uuid THEN
+			user_id = @user_id
+		ELSE true
+	END;
 
 -- name: InsertOrganizationMember :one
 INSERT INTO
@@ -22,14 +37,6 @@ VALUES
 	($1, $2, $3, $4, $5) RETURNING *;
 
 
--- name: GetOrganizationMembershipsByUserID :many
-SELECT
-	*
-FROM
-	organization_members
-WHERE
-  user_id = $1;
-
 -- name: GetOrganizationIDsByMemberIDs :many
 SELECT
     user_id, array_agg(organization_id) :: uuid [ ] AS "organization_IDs"