Expand exportable fields

[ekemeyer]

Is your feature request related to a problem? Please describe.
There are multiple sources in titleType and descriptionType for which an organization might use to assign their descriptions and titles. Currently, the asset export option does not look for all of the sources, leaving some organizations with no description in the export (see #903 as example).

Describe the solution you'd like
Expansion of the current export csv that looks across all sources and provides those values.

Describe alternatives you've considered
Batch pull down of all json for relevant assets in ams2 using curl, transforming them to pbcore, and parsing that pbcore with python script that defines all sources.

Additional context
Should be part of broader conversation re: what fields are most relevant for staff/partners.