Validation consistency for condition names & references

[d-jeffery]

Go through:

• https://github.com/openfga/api/blob/c96ec773cae9caf2a9536856bf1fa206a42ef7ef/openfga/v1/openfga.proto#L92
• https://github.com/openfga/api/blob/c96ec773cae9caf2a9536856bf1fa206a42ef7ef/openfga/v1/authzmodel.proto#L137
• https://github.com/openfga/language/blob/main/pkg/go/validation/validation-rules.go#L13

And make sure the validation is consistent for all three? Let's make it {1,50}