Conform to spec `v0.7.0`

[toddbaert]

Update the SDK to be compliant with v0.7.0.

• ensure compliance with all point in v0.7.0 (see here for complete list of changes)
  • event handlers should run immediately if the associated provider is in the state associated with that handler already
  • add new STALE provider state
  • add provider name to event details
  • update test descriptions/numbers (use: python spec_finder.py, see CONTRIBUTING.md)
• implement relevant tests
• update spec badge in README.md

[MeenuyD]

Hello @toddbaert I would like to work on this issue can you please guide how to get started

[toddbaert]

Hello @toddbaert I would like to work on this issue can you please guide how to get started

You can perhaps look at my similar changes in the js-sdk - but the description basically contains all the required behavioral changes.

[toddbaert]

I've started on this. @MeenuyD I will add you to the review.