[sdlc] Build docker image for indexer/web-server as single binary with 2 modes

The following discussion from !410 (merged) should be addressed:

• @michaelangeloio started a discussion: (+1 comment)

  See feat(go): go setup (!409 - merged) - we should probably have a single docker file with either indexer or web server mode, unless you disagree?

Summary

Create a single Dockerfile which contains all-in-one binary. Different services can be started with with different commands as entry points in respective helm charts.