[Redmine BT | Declaration form] Original numeric fields are not mentioned in the error message when filled incorrectly

Impacted version: v12.0.2

Steps to reproduce:

• From Squash, open the declaration form for an anomaly
• Enter letters in the "Estimated Time" field
• Fill in the required fields and submit the declaration

Observed result:
An error message indicates that the field value must be a valid number, but does not specify which field is causing the issue.

Expected result:
The error message should indicate to the user which field was filled incorrectly.