Algo: time series forecasting tweaks

[zqzten]

What type of PR is this?

/kind cleanup
/kind algorithm

What this PR does / why we need it:

This PR contains some tweaks for the time series forecasting algorithm. One thing should be noticed that it removes day feature for minute freq which would result in:

• minute freq would no longer capture monthly periodic features
• users can use at least one week's history to train tsf model with minute freq (previously one month needed which is a bit overkill for this freq)