fix: allow group members to read group information (#14200)

* - allow group members to read basic Group info
- allow group members to see they are part of the group, but not see that information about other members
- add a GetGroupMembersCountByGroupID SQL query, which allows group members to see members count without revealing other information about the members
- add the group_members_expanded db view
- rewrite group member queries to use the group_members_expanded view
- add the RBAC ResourceGroupMember and add it to relevant roles
- rewrite GetGroupMembersByGroupID permission checks
- make the GroupMember type contain all user fields
- fix type issues coming from replacing User with GroupMember in group member queries
- add the MemberTotalCount field to codersdk.Group
- display `group.total_member_count` instead of `group.members.length` on the account page

coderd/database/queries/groupmembers.sql

@@ -1,30 +1,14 @@
 -- name: GetGroupMembers :many
-SELECT * FROM group_members;
+SELECT * FROM group_members_expanded;
 
 -- name: GetGroupMembersByGroupID :many
-SELECT
-	users.*
-FROM
-	users
--- If the group is a user made group, then we need to check the group_members table.
-LEFT JOIN
-	group_members
-ON
-	group_members.user_id = users.id AND
-	group_members.group_id = @group_id
--- If it is the "Everyone" group, then we need to check the organization_members table.
-LEFT JOIN
-	organization_members
-ON
-	organization_members.user_id = users.id AND
-	organization_members.organization_id = @group_id
-WHERE
-	-- In either case, the group_id will only match an org or a group.
-    (group_members.group_id = @group_id
-         OR
-     organization_members.organization_id = @group_id)
-AND
-	users.deleted = 'false';
+SELECT * FROM group_members_expanded WHERE group_id = @group_id;
+
+-- 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.
+-- They only need ResourceGroup read access.
+SELECT COUNT(*) FROM group_members_expanded WHERE group_id = @group_id;
 
 -- InsertUserGroupsByName adds a user to all provided groups, if they exist.
 -- name: InsertUserGroupsByName :exec