Non-descriptive error message when a BOSH job spec property name is a prefix for another one #2495

Describe the bug
It seems that BOSH Director has the following requirement for the properties in a spec file:
No property name should be a prefix for the name of another one.
The problem is that the error message ("string not matched") is inadequate and does not point to the cause of the error.

To Reproduce
Steps to reproduce the behavior (example):
Using the bosh CLI, deploy a job with a spec file that contains something like:

properties:
  ala:
    <...>
  ala.bala:
    <...>

Expected behavior
A clear and concise description of what the problem is (e.g.: The property name "ala" is a prefix for the property name "ala.bala" and this is not allowed.).

Logs
The Ruby exception from the BOSH Director's debug logs is attached.

Versions (please complete the following information):

• Infrastructure: AWS, GCP, Azure
• BOSH version: 280.0.15
• BOSH CLI version: 7.5.0
• Stemcell version: ubuntu-jammy 22.04.1/1.351