Serializer for BigDecimal #2226

[harjitdotsingh]

This PR contains code for #2226.

[EdColeman]

There seems to be some confusion on this implementation and the need that it remains functionally equivalent to other lexicoders so that it provides consistent sort order (necessary for correct operations) and also provides a uniform user experience so that if they switch data types they would not need to change any of their business logic.

Maybe it would help if you provided concrete use cases where a BigDecimal lexicoder is necessary for your functionality.

[ctubbsii]

Closing due to lack of activity, and lack of a motivating use case. The implementation is tricky, and it's not clear there's a strong motivation to provide this. Please reopen or create a new PR if there is a strong need that warrants us providing this.