Add conda package for deephaven-core

[devinrsmith]

It may be advantageous in certain environments to provide conda native packages, so users don't need to use pip.

For deephaven-core, this would likely require jpy be a conda package as well (jpy-consortium/jpy#92).

[devinrsmith]

Note: conda users can install deephaven-core into their environment with pip; but some conda user may want to remain "pip free".

[ilyanoskov]

This is very much needed, some users are not allowed to use pip in their organisations :)