Use UDF specific names for server info file

[BulkBeing]

This change also makes the start_with_shutdown API for all servers a bit more nicer.

[vigith]

does this now run against numaflow main branch?

[vigith]

i forget why we need this sleep.

[BulkBeing]

This was done just to ensure the server is started completely before sending requests to it.

[vigith]

should we write a small utility func to do a ping and use that? else there could be flaky tests in the future. we do not have to do this in this PR.

[BulkBeing]

does this now run against numaflow main branch?

I haven't tried running a full pipeline since the only change was the server info filename. I copied it from numaflow-go.

[BulkBeing]

Tested with v1.2.0-rc1 release of numaflow:

kubectl apply -n numaflow-system -f https://github.com/numaproj/numaflow/releases/download/v1.2.0-rc1/install.yaml

And ran a source that pulls from kafka:

➜  kubectl logs -f kafka-source-rust-in-0-rzxng -c numa
{"level":"info","ts":"2024-03-28T06:51:36.390248207Z","logger":"numaflow.Source-processor","caller":"commands/processor.go:48","msg":"Starting vertex data processor","version":"Version: v1.2.0-rc1, BuildDate: 2024-03-26T16:15:00Z, GitCommit: 0a1a2e8b85f98e15d3e6a71eb8c07f591e796ea6, GitTag: v1.2.0-rc1, GitTreeState: clean, GoVersion: go1.21.8, Compiler: gc, Platform: linux/arm64"}
{"level":"info","ts":"2024-03-28T06:51:36.39428027Z","logger":"numaflow.Source-processor","caller":"fetch/source_fetcher.go:43","msg":"Creating a new source watermark fetcher","pipeline":"kafka-source-rust","vertex":"in"}
{"level":"info","ts":"2024-03-28T06:51:36.394451894Z","logger":"numaflow.Source-processor","caller":"fetch/processor_manager.go:143","msg":"Refreshing ActiveProcessors ticker started","pipeline":"kafka-source-rust","vertex":"in"}
{"level":"info","ts":"2024-03-28T06:51:36.395726262Z","logger":"numaflow.Source-processor","caller":"jetstream/kv_store.go:264","msg":"Successfully created watcher","pipeline":"kafka-source-rust","vertex":"in","kvName":"default-kafka-source-rust-in_SOURCE_PROCESSORS","watcher":"default-kafka-source-rust-in_SOURCE_PROCESSORS"}
{"level":"info","ts":"2024-03-28T06:51:36.395787054Z","logger":"numaflow.Source-processor","caller":"jetstream/kv_store.go:199","msg":"Watcher initialization and subscription got nil value","pipeline":"kafka-source-rust","vertex":"in","kvName":"default-kafka-source-rust-in_SOURCE_PROCESSORS"}
{"level":"info","ts":"2024-03-28T06:51:36.396084427Z","logger":"numaflow.Source-processor","caller":"jetstream/kv_store.go:264","msg":"Successfully created watcher","pipeline":"kafka-source-rust","vertex":"in","kvName":"default-kafka-source-rust-in_SOURCE_OT","watcher":"default-kafka-source-rust-in_SOURCE_OT"}
{"level":"info","ts":"2024-03-28T06:51:36.39611551Z","logger":"numaflow.Source-processor","caller":"jetstream/kv_store.go:199","msg":"Watcher initialization and subscription got nil value","pipeline":"kafka-source-rust","vertex":"in","kvName":"default-kafka-source-rust-in_SOURCE_OT"}
2024/03/28 06:51:36 Server info file /var/run/numaflow/sourcer-server-info is not ready...
2024/03/28 06:51:37 ServerInfo: &{uds rust 0.0.1 map[]}
2024/03/28 06:51:37 UDS Client: unix:/var/run/numaflow/source.sock
{"level":"info","ts":"2024-03-28T06:51:37.400538181Z","logger":"numaflow.Source-processor","caller":"sources/source.go:250","msg":"Start processing source messages","pipeline":"kafka-source-rust","vertex":"in","isbs":"jetstream","to":["default-kafka-source-rust-out-0"]}
{"level":"info","ts":"2024-03-28T06:51:37.400588097Z","logger":"numaflow.Source-processor","caller":"udsource/user_defined_source.go:166","msg":"Starting user-defined source...","pipeline":"kafka-source-rust","vertex":"in"}
{"level":"info","ts":"2024-03-28T06:51:37.400618014Z","logger":"numaflow.Source-processor","caller":"metrics/metrics_server.go:237","msg":"Generating self-signed certificate","pipeline":"kafka-source-rust","vertex":"in"}
{"level":"info","ts":"2024-03-28T06:51:37.400637264Z","logger":"numaflow.Source-processor","caller":"forward/data_forward.go:132","msg":"Starting forwarder...","pipeline":"kafka-source-rust","vertex":"in"}
{"level":"info","ts":"2024-03-28T06:51:37.401199844Z","logger":"numaflow.Source-processor","caller":"metrics/metrics_server.go:269","msg":"Not enabling pprof debug endpoints","pipeline":"kafka-source-rust","vertex":"in"}
{"level":"info","ts":"2024-03-28T06:51:37.40123476Z","logger":"numaflow.Source-processor","caller":"metrics/metrics_server.go:282","msg":"Starting metrics HTTPS server","pipeline":"kafka-source-rust","vertex":"in"}