Cleanup of .env content; Add debezium/perf.

[jcferretti]

On .env files:

• Remove unused definitions.
• Rename PORT to DEEPHAVEN_PORT; since environment variables override, it is desirable to have something more specific to avoid somebody's personal environment definitions mixing things for them.

Simplify memory configuration for the server definition in docker-compose-common.yml.

[devinrsmith]

I was under the assumption you'd be removing our docker deploy resource limits - was that going to be separate?

I do want to take the time Monday and run the compose file myself.

[jcferretti]

I was under the assumption you'd be removing our docker deploy resource limits - was that going to be separate?

I do want to take the time Monday and run the compose file myself.

Somehow I lost that change; done.

[devinrsmith]

Let's give @niloc132 a chance; and I still want to take a pass at running it soon.

[niloc132]

after the fact review: prefer quotes for these (like you did in line 49) since yaml can do some super awesome type coercion when it doesn't know what you might be trying to express