Support expression in time field for timeseries

[gingerwizard]

Is your feature request related to a problem? Please describe.

Currently if you using the TimeSeries component of the query builder, the user is forced to select a time field. Its not uncommon for users to a time field encoded in a different type e.g. int. ClickHouse supports expressions to allow conversion if required.

Describe the solution you'd like=

Please allow free typing of an expression in the Timefield input or allow switching to an expression mode.

Additional context

This needs alittle care since ther time field is used in the WHERE clause e.g. $__timeFilter(created_at) - this should probably use the alias time or id expect issues on some expressions.

[SpencerTorres]

This is now possible in v4

The $__timeInterval macro is still added when in Time Series Aggregate mode, but the query still functions as expected. time alias is also handled in the query. If the user wanted to exclude this macro they could use Table Aggregate mode.