Refactor / Improve the way we handle getting gas estimate currently

Currently GasFeeController returns the gas estimates using current network and account type, if network is advanced and supports EIP-1559, there is no way to get gas estimates for a legacy transaction on that network using GasFeeController. It will be nice to change gas fee controller to return gas estimates after considering the type of transaction, for for instance a type-0 transaction on a network supporting EIP-1559 we should be able to get `gasPrice` estimates.

Thus we need to refactor GasFeeController, TransactionController and also UI code for this. As metamask see a new transaction it will get gasEstimates using its type, it will be stored in state in a Map. As UI starts polling for gasFeeEstimates it can continue to update this map in the state. All of the UI components can use this map in state as source of gas estimates. This will also work well in scenario when the user sends request of different types of transactions to metamask.

Together with the task: https://github.com/MetaMask/metamask-extension/issues/12276, this will simplify our UI.

Start by tracing GasFeeController and TransactionController, then follow the UI code that requests and polls gas estimates. Compare the requested transaction type with the current network and account-based flow, and review issue #12276 for related context. Done means estimates are stored and updated per transaction type so both legacy and EIP-1559 transactions can use the appropriate values.

Written by the indexing model from the issue text.