proxy: Make retries configurable and record it. (#7438)

## Problem

Currently we cannot configure retries, also, we don't really have
visibility of what's going on there.

## Summary of changes

* Added cli params
* Improved logging
* Decrease the number of retries: it feels like most of retries doesn't
help. Once there would be better errors handling, we can increase it
back.

proxy/src/serverless/backend.rs

@@ -108,6 +108,8 @@ impl PoolingBackend {
             },
             &backend,
             false, // do not allow self signed compute for http flow
+            self.config.wake_compute_retry_config,
+            self.config.connect_to_compute_retry_config,
         )
         .await
     }