[Feature] Adds Router Path For Economic Surveys

[deeleeramone]

1. Why?:

   • This path is being created for organizational purposes, and it will fill out over time (JOLTS, etc can go here).

2. What?:

   • Adds a path to the /economy router: survey.

   • Adds endpoints:

     • university_of_michigan
     • sloos (Senior Loan Officers Opinion Survey).
     • economic_conditions_chicago
     • manufacturing_outlook_texas

3. Impact:

   • No breaking changes.
   • Additional maintenance of more endpoints and models.

4. Testing Done:

   • Unit/Integration tests.
   • CLI