build: Automated releases w/ conventional commits; Prep for npm package...

build: Automated releases w/ conventional commits; Prep for npm package publish of calc and api-sidecar; (#298)

- Releases process automation with conventional commits, including auto CHANGELOG generation
- Convert @substrate/calc package to npm dependency
- Prepare @substrate/calc package for publish to npm
- Prepare @substrate/api-sidecar package for publish to npm