[FR] Streamed code search

[brendan-kellam]

zoekt supports streaming search results via the GraphQL API. We could leverage this capability in Sourcebot to stream in search results as they load in, reducing the Time to First Search Result (TFSR).

Related: #504

[tchikh411]

Hi @brendan-kellam, I can take this one..

[brendan-kellam]

Hey @tarangchikhalia - I think I will take this one on as it has entered our critical path for feature development

[brendan-kellam]

Shipped in #623