[Feature] Enhance DyDx.Exchange Support

[michael-spengler]

The following features shall be implemented additionally within class DyDxService:

• [ ] Deposit / Withdraw to / from Perpetual Account --> https://docs.dydx.exchange/#deposit-withdraw-to-perpetual-account
• [ ] Place Perpetual Order --> https://docs.dydx.exchange/#perpetual-place-order

[michael-spengler]

just created a reddit post looking for some supporters as this seems not too easy.

Listing some of the challenges which I faced underway:

although the docs seem to say it is:

[michael-spengler]

also raised an issue about general documentation weak spots here: https://github.com/dydxprotocol/perpetual/issues/255