feat: E2E proxy scenarios and dev env setup (#2000)

* feat: e2e tests for proxy communication

* chore: merge ss / cs dockerfiles into single multi-sage file

* chore: improve compile scripts

* chore: consolidate dockerfile for cs / ss usage.

* chore: ci fixes

* chore: ci fixes

* chore: ci fixes

* chore: improve local env setup

* chore: update readme, add looser healtchecks for slower envs.

* chore: dependencycheck version bump

* chore: disable dependencycheck during its outage

* chore: documentation update, improve docker compose

* chore: documentation update