Replace current timezone selector

[removed-account-123]

Now it is not easy and comfortable to choose timezone. It should hint or autocomplete user's query. It should be sorted by ABC. (Selector with search function?).

Connected to #625

[ksendart]

angular/components#7835

[jrood]

The author of angular/components#7835 seems to be waiting feedback regarding a11y, so if you have any, please leave it there.

[bwsw]

@ershovaelena
support default timezone, specified globally in config and remembered in account tags for account.

[elenaustyugova]

Depreciated. A default timezone and account tags support TBD in #977