Fix ObservableQuery result dirty check with last.reportedResult

[javier-garcia-meteologica]

When notifyOnNetworkStatusChange is enabled some watchQueries get stuck in loading: true, partial: true after calling reobserve/setVariables even if the underlying network request has already returned a successful result.

In particular, this bug happens when a reobserved query returns the same data with the new variables as before, or when the query is simply refreshed.

1: loading: false, data           ->   isDifferentFromLastResult=true, savedAsLastResult=true
2: loading: true, partial: true   ->   isDifferentFromLastResult=true, savedAsLastResult=false
3: loading: false, data           ->   isDifferentFromLastResult=false, savedAsLastResult=false, suppressed

In this PR I create the variable last.reportedResult to keep track of last reported result, which may be different than last.result. It avoids leaving queries stuck in loading=true forever.

Related to #9367

Checklist:

• If this PR is a new feature, please reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests

[meteomaragliano]

@jpvajda any updates on this issue?

[jpvajda]

@meteomaragliano hello! Thanks for the follow up, I'll see if I can get someone from the team to review this PR soon.

[javier-garcia-meteologica]

I just run the test of this PR on the main branch and it passed. The problem addressed by this PR seems to be fixed in recent versions of apollo client.