Allow wallet only segwit capable coins in orderbook method + related bugs

[smk762]

Describe the bug
Recently, coins such as LTC and DGB were marked as wallet_only to motivate users to use LTC-segwit and DGB-segwit instead.

This results in the following response from the API when attempting to request the orderbook.

Note: The error message in v1 is actually incorrect as LTC was the rel coin, not the base coin. v2 method error is ok.

The v2 response has some unexpected data also.

This entry specifies LTC, but for an LTC-segwit address. I've confirmed that order was created on 2.0.0-beta_91be151 with LTC-segwit enabled as LTC-segwit, via the start_simple_market_maker_bot method configured as below

What do you want

• It would be nice to be able to query the orderbook for LTC and rather than get an error, see the results for LTC-segwit. In the past requesting either LTC or LTC-segwit would return the same orderbook, though we didnt have one of them marked wallet only so likely this case was never considered.
• Optionally fix the v1 error message. Not really important though as v2 orderbook method deprecates the old one.
• Correctly attribute LTC-segwit orders in the orderbook.