Add enforceActions support in ReactiveConfig and Derivations

[pavanpodila]

Support the enforceActions feature of MobX JS

[katis]

I know that in Mobx JS enforced actions are disabled by default but I'd suggest that we enabled them by default, especially if we can get async @actions to work. This way making actions to mutate state would be the norm, and making state changes everywhere willy-nilly would be the hacky "quick&dirty" way.

[pavanpodila]

Agree @katis, let me try that in the next PR. Have a bunch of tests that need to be changed as we are mutating lot of the observables outside actions.

More precisely, ~88 tests will fail 😬 if we enable EnforceActions.always as the default. Currently I have set it to EnforceActions.never

[katis]

@pavanpodila What about using observed as the default? That's what I use in all my JS projects.

[pavanpodila]

Ya, that would be good. Even there about 62 tests are failing

[pavanpodila]

I can take it up once we merge this. Please review :-)

[katis]

If enforceActions were changed to be variable in the context, you could just disable enforcement in the test files.

Edit: nvm, it already is configurable

[pavanpodila]

Fixed in #88. Will open a separate issue for a stricter enforcement