Increase default projection retries

[zenyui]

Is your feature request related to a problem? Please describe.
Projection retries are too low, so it restarts the projection actor too frequently

Describe the solution you'd like
increase the default projection retries to much higher, and make it configurable via an env var, like COS_READ_SIDE_PROJECTION_RETRIES

For now, we can add this setting but leave it out of the docs so we can play with it.

See the application.conf file for other examples of configurable env var settings with defaults

Describe alternatives you've considered
n/a

Additional context
COS implements the read handler with Akka projections, and when a read side fails, Akka will retry the projection up to the configured times, then restart the actor. Long term, we would like a more graceful akka projection implementation, but for now, it would be nice to increase this default retry and make it configurable.

[Tochemey]

@zenyui I think you mean the interval between projection retries which is 1s set here. I will suggest we call that env var COS_READ_SIDE_PROJECTION_RETRIES_INTERVAL for the meantime.