Support downloading of segment from controller on load error in Realtime table

[icefury71]

Currently, for realtime Pinot table, a segment load error (during server restart for eg) will result in the segment going into an ERROR state. This might happen if the segment was not sealed properly (server got shut down) or default column got removed.

This can be resolved by adding a retry logic to fetch the segment from Controller (this is what happens today for Offline Table).

CC @Jackie-Jiang @fx19880617

[Jackie-Jiang]

#6647

[mcvsubbu]

The segment download code is the same on the server, with retry logic -- whether realtime or offline

[Jackie-Jiang]

@mcvsubbu For real-time table, when server finds a local copy of the segment, but cannot load it, server will throw exception. The proposal here is to download a new copy from the controller when server fails to load the local copy.