Ensure types are generated when new contexts are merged into master branch

[kriswest]

A PR (#747) is failing to build because it references another context type that was added in 2.0. In the PR the author has manually added the new context type with the reference. However, as types have not yet been generated for 2.0 (awaiting #745) the referenced type is missing.

Update the github actions to:

• attempt to run type generation from context schemas on PRs (to check that they compile without error)
• run type generation on merge to master as part of deployment, so that authors do NOT have to add the typescript manually, prior to deploying.

[kriswest]

Also consider releasing NPM module as a 'next' version with the newly generated types.

[kriswest]

Heavily related to:

• Should we split context & intent out of the main FDC3 standard? #940

[kriswest]

superseded by #940