* Sketch out how to support different bridge pallet instances
* Create a common interface for using pallet instances
* Start introducing generic instance parameter
Attemps to make the compiler happy, but I'm having second thoughts about
this approach. Commiting now as a way to have a checkpoint, but I think
I'm going to need to re-consider my approach here.
Ideally I want a change which introduces minimal changes, but this seems
to be propagating around the codebase in ways I don't want.
* Use trait objects instead of generics
* Implement traits for Boxed trait objects
This is done in order to statisfy trait bounds by types
which use these new trait objects
* Remove Clone usage for sync parameters
* Remove implementation of Default for sync params
* Require that BridgeInstance implements Debug
* Ensure that BridgeInstance trait implements Send/Sync
* Add documentation related to instances
* Rust Fmt
* Remove needless format
* Make instance CLI option case insensitive
* Replace `with_*` constructors with `new`
* Clean up usage of instance structs
* Enforce a default instance in the CLI params
* Build sync params as we process input from CLI
* Remove case insensitivity from sub-tx-mode
I think this should happen, but maybe as part of a different PR
* Process default Eth contract deployment config in CLI
* Build EthereumExchangeParams in CLI
* Process EthereumExchangeSubmitParams params in CLI
Svyatoslav Nikolsky