feature: add @IsTime

[kimsey0]

Description

It's currently not possible to validate time values like 12:34 using class-validator. These may come the time input HTML element.

Proposed solution

Add a new @IsTime validator which calls the isTime function from validator.js.

[kimsey0]

I just now noticed there's @IsMilitaryTime. 🤦 (The believe the term "military time" is basically unknown outside the United States.)

I'd still suggest an @IsTime that just allows passing in the options for the validator.js isTime.

[braaar]

Perhaps it would be a good idea to start using isTime for @IsMilitaryTime and add @IsTime as an alias for it. PR welcome.

[braaar]

I'm moving this to the discussion tab, as we are trying to keep the issue count low. Please see this issue for an explanation.