Support blob triggers for premium storage on consumption plan

See https://github.com/Azure/azure-webjobs-sdk-script/issues/773 for full context. Work was done to make sure that premium storage works for input and output scenarios but there are blocking issues that prevent trigger scenarios and that is what this issue tracks.

The main blocking issue is that blob logging is not supported for premium storage and the consumption SKU relies on blob logging to detect changes.

Start with the linked azure-webjobs-sdk issue 773 and trace how consumption-plan blob logging detects changes for premium storage. The issue names no files, tests, or entry points, so map the trigger and logging paths before deciding on an implementation. Done means blob triggers work for premium storage on the consumption plan.

Written by the indexing model from the issue text.