Show alert on confirmations with high network congestion and volatile gas estimations

#Description
As a user, I want to be notified if there is high network congestion and gas estimations are currently volatile

#Situation
GIVEN: I am confirming a transaction (transaction confirmation, approve, etc)
WHEN: when there is high network congestion and gas estimations are volatile
THEN: I should get an alert notifying me of high gas prices

[Error use cases](https://docs.google.com/spreadsheets/d/195Vw7sJcAeIzJFrpH1mE7MNVtb8tyPTJXADUvv4GQ3A/edit#gid=0)

Start by tracing the transaction confirmation and approval entry points, then review the linked Error use cases spreadsheet for the expected scenarios. Done means showing an alert when network congestion is high and gas estimates are volatile across the stated confirmation flows, with the behavior verified for each case.

Written by the indexing model from the issue text.