[CAL-4937] Operation Fast Embed

[PeerRich]

embed (iframe):

• render UI first, then wait for it to finish (instead of loading first, then full UI)
• parallelise and speed up salesforce and routing form calls

cal atoms:

• reach feature parity (design and functionality)
• figure out how /router from routing form can redirect to atom

once done, add and rename embed generator:

_{From SyncLinear.com | CAL-4937}