feat(publish): Add version bump script

[Lms24]

This PR (unfortunately) adds lerna to our repo to use it as a mechanism of bumping all our package versions. We need this for the craft publishing process.

For future readers, here are some reasons for choosing lerna:

• Nx doesn't have a version bump command built in :(
• I tried to use the Nx semVer plugin but this tool does too much for our purposes
  • it creates git tags (can't disable this)
  • it automatically determines if the version should be a major/minor/patch bump
  • we could only manually override the decision to bump to the next major/minor/patch but we can't just specify a version.
  • Because of these limitations and for time reasons we chose not to pursue this approach further
• I tried to use yarn version but this would only bump the version of the respective package, but not of the package's dependencies.
  • This caused yarn install failures because of dependency missmatches after bumping the versions.

Lerna has a lerna version command which lets us set a specific version on our terms. So we're welcoming it back for now until Nx hopefully figures this out.

Furthermore, the PR adds a pre-release script we need for craft later on

ref #50

[AbhiPrasad]

Maybe one day we try https://rushjs.io/ - which has this stuff built in.