feat: Remove sales channels from pub keys (#6876)

**What**
- Add workflow + step for detaching sales channels from pub API keys
- Tweak linking error message to be more helpful
- Add `removeRemoteLink` step to delete API key workflow

packages/medusa/src/api-v2/admin/api-keys/validators.ts

@@ -79,7 +79,10 @@ export class AdminRevokeApiKeysApiKeyReq {
 
 export class AdminDeleteApiKeysApiKeyReq {}
 
-export class AdminPostApiKeysApiKeySalesChannelsBatchReq {
+export class AdminPostApiKeysApiKeySalesChannelsBatchAddReq {
   @IsArray()
   sales_channel_ids: string[]
 }
+
+// eslint-disable-next-line max-len
+export class AdminPostApiKeysApiKeySalesChannelsBatchRemoveReq extends AdminPostApiKeysApiKeySalesChannelsBatchAddReq {}