* Refactor fee provider
The fee provider ended up glued with a hardcoded factory. This PR:
* removes this glue and uses the DI to register fee provider for a network. (allows plugins to add their own fee providers, for any network
* Add a 10 second timeout to mempoolspace fee fetching as they are slow at times
* use linear interpolation for mempool space fee estimation
* fix upper bound
* Add tests, rollback pluginify FeeProvider
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Co-authored-by: nicolas.dorier <nicolas.dorier@gmail.com>
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