Use TS Morph to generate type predicates

[Roaders]

adresses #1268

This is a very rough cut and really just proves that what I was planning does work.

We could generate the predicates in a different file if we wanted to. We could also generate union types of the request and response messages if we wanted to.

I had some issues getting ts-node working initially hence the extra tsconfig file. We can move the generate-type-predicates file into the root of the project if desired.

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[Roaders]

We should probably run tsc on the generated ts code after generation is complete to make sure it's all good. Does that currently happen?

[Roaders]

we should probably also generate type predicates for the context objects as well.

[kriswest]

We should probably run tsc on the generated ts code after generation is complete to make sure it's all good. Does that currently happen?

We currently just run the type generation and then the linter vai teh prebuild npm script, which I think would error out if there was a problem with the generated code:

FDC3/package.json

Line 26 in aa276dd

"lint": "eslint src/ test/ --ext .ts --fix",

In the fdc3-for-web branch this is now set to happen on a pre-commit hook.

I haven't had time to take a proper look at this PR yet, but I wanted to get you an answer on the above.

[kriswest]

we should probably also generate type predicates for the context objects as well.

Yes we should! This is the PR that touched those last and introduced some util functions based on them: https://github.com/finos/FDC3/pull/1139/files

If you have a minute do please take a look and compare notes.

[kriswest]

@Roaders do you still want to do this? I had review this (finally) on my todo list for this week and next.

[Roaders]

yes I do. I actually meant to extend it a bit. A union type for all the request messages would be very useful for Discriminated unions and Exhaustiveness checking when handling request messages in the root agent for example.

[Roaders]

oh dammit. I've accidentally closed this. Sorry, I'll raise a new PR.

[Roaders]

New PR: #1387