Add formulas to work with Clickhouse Dictionaries

[skaradub]

Hello there!

Dicts are very useful when you work with Clickhouse DataBase and Huge Datasets.
Please, add Formulas to use dictionaries in Datalens

Clickhouse functions are as well that (IMO) should be made

dictGetStringOrDefault
dictGetUInt64OrDefault
dictGetFloat64OrDefau

and in DataLens these have parameters

func('dict':String,'field':String,'key':int64)
or
func('dict':String,'field':String,'key':diffTypes,['key2']:diffTypes) -- to use with tuple dicts

Regards,
Yury

[KonstantAnxiety]

Hey @skaradub!

Closing this issue in favour of #106. Feel free to add comments regarding the desired behaviour/features there.