Be able to create a random timestamp

[JimPaine]

Description

When generating something other than logs, such as search queries for Splunk it would be helpful to be able to randomize the date / timestamp that is used, rather than being limited to the current UTC timestamp.

[JimPaine]

Currently thinking it would be a good to idea to change the type handling in the random between token so that when lignator first loads and parses the tokens it works out the type to allow us to between other types, such as

• DateTime
• Timespan
• integer
• double
• decimal

https://github.com/microsoft/lignator/blob/main/src/TokenMapper.cs#L62-L63