Add support for indexing senotypes into Elasticsearch

[maxsibilla]

We can potentially create a new subset of URLs prepended with senotype for the various reindex endpoints.

• The existing senotype editor will need to be updated to call these endpoints upon creating/saving senotypes
• We will reindex off of the existing MySQL database (we can discuss backend changes later)

[maxsibilla]

New methods:

• /senotype/<index_without_prefix>/search POST (This may not be necessary)
• /senotype/reindex/ PUT
• /senotype/reindex-all PUT

In search-config.yaml we will add a new index under indices called "senotype" with public and private properties:

• sn_<dev/prod>_public_senotypes
• sn_<dev/prod>_private_senotypes

We will need a new senotype-default-config.yaml that for now can just be a copy of file-default-config.yaml for now