Add market history plugin asserts

[oxarbitrage]

Fix for issue #2021

I was expecting that calls like get_account_history and related will need account_history_plugin however it seems this is not the case as when i added asserts i got failures in the history_api_tests.

So i left those alone and just added asserts to the ones related to market_history_plugin where missing. This are are the same calls mentioned in the issue: get_fill_order_history and get_market_history.

[abitmore]

Thanks.
We'll need to think about the account history APIs later. It's more about how clients handle the errors (will the change break the client apps).

[abitmore]

Thanks.