Create workspace-wide setting to toggle if pre-sync checks run and prevent syncs

[evantahler]

After #12281 we will be running the CHECK (both Source and Destination) command before every sync. We could add an option to disable this.

[evantahler]

Closing this issue. As CHECKs are fast (~15s or shorter), we don't want to add more confusion for our users by introducing a new (workspace-wide) setting.

If checks become even slower, we can revisit this choice.

cc @sherifnada @misteryeo