[IMPROVE] funds menu

[hjoaquim]

After the refactor on the fund's menu on #4068 by @Mael-J there are a couple of things that can be improved to match other sections of the terminal.

Make the funds menu usable on:

• SDK : currently there is no mapping for the SDK. This might require some work, as the function that loads the asset is returning a custom object mstarpy.Funds. Although the other functions then return pd.Dataframe this behavior kinda breaks the standard behavior of not having custom objects but dataframes instead.
• Forecasting menu : for the same reason as described above - it will require us to pass a usable dataframe to the forecasting menu to work with.

Deprecate:

• investpy dependency - not sure if we're still using it anywhere, if not, the dependency should be removed.
• investiny dependency - not sure if we're still using it anywhere, if not, the dependency should be removed.
• investingcom*.py (views + models) that are not used anymore.
• remove unit/integration tests related with the above points

Tests:

• add integration tests for the funds menu
• improve unit test coverage for funds_controller, mstarpy_model and mstarpy_view

[jmaslek]

think we have hit everything here except linking to forecast menu.