chore(payment-processor): batch fee usd limited

[olivier7delf]

Add the possibility to add/skip the batch fee amount in USD limit using the payment-processor methods. e.g: activated, a payer will pay no more than $150 batch fees.

To make PR understandable, it merges into fix/btach-conversion-capped. The PR is OK when merging directly on master.

[bertux]

Add the possibility to limit batch fee in USD using the payment-processor methods.

Question: within TESTS (private network) currencyManager cannot be used to get a conversion path from a token to USD, is there another solution to test it?

I've shown @olivier7delf how to add support for private network in currencyManager as it's done for testnets. So tests will be able to use it.

[coveralls]

Coverage decreased (-0.05%) to 88.912% when pulling 922d4bc357a30c71cd5e308d15772d764072362a on chore/payment-processor-batch-fee-usd-limited into d08158c86588ccbf7c840387fe7abc970777502f on master.