fix get_current_date() & now()

[seralekseenko]

Which are date/time-function actual in code?

Problem: there are we have two functions for getting a datetime:

• in calls/generic_calls.py which uses system time in container
• in utils/common.py which uses NASDAQ timezone...

What I propose: use one timezone from market.
For example, there is helpful function in Alpaca's API: TradingClientSingleton.get_instance().get_clock().

From doc:

"""
Gets the current market timestamp, whether or not the market is currently open, as well as the times of the next market open and close.

Returns:
     Clock: The market Clock data
"""

[seralekseenko]

Next task: realize host's system time!

[seralekseenko]

Next task: OPTIMIZATION