[Task]: Implement initial opportunities endpoint

[acouch]

Summary

Add the models, schemas, and other items for a /opportunities endpoint. Consider what we want the endpoint to take in as parameters for example purposes. Return some basic outputs.

Return data from topportunity table

OPPNUMBER as Funding Opportunity Number 
OPPTITLE as title
OWNINGAGENCY as agency
OPPCATEGORY as category
IS_DRAFT = true / publshed

Acceptance Criteria

• Validate the endpoint can fetch out of the database and return as expected