Removing trading pair dependency

[TheLedgerOfJoudi]

I moved the draft PR #801 here with the correct branching out of develop. This PR holds a better descriptive name, as well, as I added more traits to resolve the clear dependency.

[wer1st]

You missed the important part - the removing of build dependecies in Cargo.toml

[TheLedgerOfJoudi]

Removed trading_pair::Config as a supertrait in src/lib.rs from all pallets.
Removed trading_pair as a build dependency from pallets which do not require it in mock initializations.
T::Trait is requiring fully qualified path for disambiguation because the type could derive from multiple pallet configs.

[github-advanced-security]

clippy found more than 10 potential problems in the proposed changes. Check the Files changed tab for more details.