Parent #13326

This PR supports below scan states:

• Provisioning (displays provisioning state items using Calypso's logic)
• Invalid: UnAvailable and Unknown (displays full screen error)

Provisioning State	Invalid State

EDIT:
This PR also updates scanning state description for initial scan (Calypso's logic).

Scanning (MostRecentStatus.isInitial = true)	Scanning (MostRecentStatus.isInitial = false)

To test

Prerequisite:

• Make sure both Scan feature flag and MySiteImprovements flag are set to on in the App settings.
• You have access to WP.com account with a site having scan capability and threats (e.g. https://pressable-jetpack-daily-scan.mystagingwebsite.com). Server credentials should be set on the site.

You can test the changes in either ways:

1. by running newly added tests in ScanStateListItemsBuilderTest and ScanViewModelTest

or

2. by commenting these lines in FetchScanStateUseCase, adding below lines for required scan state at line 39 and accessing the scan screen in the app.

PROVISIONING State

emit(Success(ScanStateModel(state = ScanStateModel.State.PROVISIONING)))
return@flow

UNKNOWN State

emit(Success(ScanStateModel(state = ScanStateModel.State.UNKNOWN)))
return@flow

UNAVAILABLE State

emit(Success(ScanStateModel(state = ScanStateModel.State.UNAVAILABLE)))
return@flow

SCANNING State

emit(Success(ScanStateModel(state = ScanStateModel.State.SCANNING, mostRecentStatus = ScanProgressStatus(isInitial = <true/false>, startDate = Date(0)))))
return@flow

Merge Instructions

1. Make sure PR Issue/13326 scan full screen loading & error handling #13920 is merged to develop
2. Remove the "Not Ready for Merge label"
3. Merge this PR

PR submission checklist:

• I have considered adding unit tests where possible.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.