deployctl github action is missing a lot of features from the cli version

[lowlighter]

The GA significantly deviates from the deployctl, causing a lot of headaches and the need of hacks to make it work with "modern deno":

• no auto-discovery of deno.jsonc
• needs to manually re-specify project, entrypoint and other flags despite being present in deno.jsonc (required by action.yml)
• import map does not default to deno.jsonc
• using deno.jsonc as import map can error as it expects JSON (not JSONC)
• a "simple translation" of deno.jsonc to imports.json doesn't work oob because it cannot resolve resolves sub-exports (e.g. "@x/y/z")
• diverging options between cli and GA (not all options are available, for example passing env vars)