Description

Implement the schemas related to project funding. These include the project_checkbook and project_fund tables. It also includes the fund_category and project_fund_stage enums.

Full ERD for reference

Acceptance Criteria

[x] A project_fund_stage enum exists, matches the options listed in the reference ERD/sql, and is exported from the project schema file (this makes it visible to future migrations. I am prescriptive on which file to use because it will only be used by project schemas and colocating the definition with its only use makes it easier to read.)
[x] A fund_category enum exists, matches the options listed in the reference ERD/sql, and is exported from the file where it is defined (this makes it visible to future migrations. I'm not prescriptive on which file should hold the enum because it needs to be shared across two different schemas.)
[x] A project_fund schema exists and mirrors the columns documented in the ERD/reference SQL table
[x] A project_checkbook schema exists and mirrors the columns documented in the ERD/reference SQL table
[x] The database columns use snake_case and the javascript variables use camelCase

Blocked by the schemas created in #210