[Feature]: Add support for estimating fees for sBTC contract calls

[djordon]

Feature - Add support for estimating fees for sBTC contract calls

1. Description

1.1 Context & Purpose

When broadcasting contract calls, we need to make sure that we submit the transaction with enough fees for the contract call to be confirmed promptly. Add some functions that call a stacks nodes or the stacks/Hiro API for fee estimates.

Data sources

1. The stacks mode might have the /v2/fees/transaction endpoint (from docs.stacks.co, docs.hiro.so, and the code referencing the stacks-core node API but missing from the rpc-endpoints.md file in the repo stacks-core repo).
2. The stacks node has the /v2/fees/transfer endpoint.

2. Technical Details:

2.1 Acceptance Criteria:

• We can get an relatively accurate estimate of the contract call fees.

3. Related Issues and Pull Requests (optional):

This is part of #44 and recently came up during this discussion #228 (comment).