Add support for MSC4155 (#1013)

[rendered msc here](https://github.com/Johennes/matrix-spec-proposals/blob/johannes/invite-filtering/proposals/4155-invite-filtering.md). Closes #836.

Co-authored-by: nexy7574 <git@nexy7574.co.uk>
Reviewed-on: https://forgejo.ellis.link/continuwuation/continuwuity/pulls/1013
Reviewed-by: nex <nex@noreply.forgejo.ellis.link>
Co-authored-by: Ginger <ginger@gingershaped.computer>
Co-committed-by: Ginger <ginger@gingershaped.computer>

src/core/error/response.rs

@@ -73,6 +73,7 @@ pub(super) fn bad_request_code(kind: &ErrorKind) -> StatusCode {
 		| ThreepidAuthFailed
 		| UserDeactivated
 		| ThreepidDenied
+		| InviteBlocked
 		| WrongRoomKeysVersion { .. }
 		| Forbidden { .. } => StatusCode::FORBIDDEN,