Test TS translation of the new MobX spine JS features

In the past years, several features and tests were added to the original MobX spine written in JavaScript. An attempt was made to translate all these features to TypeScript, and this release is the result. Time to test!

Bugfixes

Just some bugfixes

Add support for base64 files

v0.30.2-beta

First attempt to add support for base64 files

Actually build the features added in v0.30.0-beta

v0.30.1-beta

Build the new features

Add support for the 'health features'

v0.30.0-beta

Add negative ids, copy, and validate

Target es5

v0.29.21-beta

target es5

Add static Model.primaryKey constant

v0.29.20-beta

Add primaryKey constant with value "id"

Try older axios version

v0.29.19-beta

Try older axios version

Check relevance before calling fromBackend

0.29.18-beta

Check relevance before calling fromBackend on relations

Remove the _meta handling code

Revert "Attempt to handle _meta responses"

This reverts commit b3d09b7ec8bf0047e37cbed62d1502163317c02a.
The JavaScript mobx-spine doesn't seem to handle _meta responses and this seems to be the cause of a tracy integration test failure, so I will disable this and see what happens.