SM-837: Add Secret and Project Length Restrictions

[coltonhurst]

Type of change

- [ ] Bug fix
- [x] New feature development
- [ ] Tech debt (refactoring, code cleanup, dependency upgrades, etc)
- [ ] Build/deploy pipeline (DevOps)
- [ ] Other

Objective

Add Secret and Project length restrictions for each field:

• project_name <= 500
• secret_key <= 500
• secret_value <= 3000
• secret_note <= 7000

Code changes

• error.rs: Add the FieldLengthExceeded error
• project/create.rs: Add and call the validate function
• project/mod.rs: Add the project_name max const
• project/update.rs: Add and call the validate function
• secret/create.rs: Add and call the validate function
• secret/mod.rs: Add the secret key, value, and note max const's
• secret/update.rs: Add and call the validate function

Before you submit

• Please add unit tests where it makes sense to do so (encouraged but not required)