Add validation for AWS secret name format and clarify form descriptions

Problem/Motivation

The AWS Secrets Manager module currently allows any string to be entered as a secret name. However, AWS has specific restrictions on valid secret name characters. Accepting invalid input may lead to runtime errors when trying to interact with AWS APIs.

Additionally, several form field descriptions are too generic or unclear, which can confuse users about what is required or expected.

Steps to reproduce

1- Navigate to the key add/edit form using the AWS Secrets Manager provider.
2- Enter an invalid secret name (e.g., invalid name).
3- Submit the form.

Expected result:
The form should block submission and show a clear error if the secret name doesn't meet AWS format requirements.

Actual result:
The form accepts the value, but the secret fails at runtime when the module attempts to interact with AWS APIs.

Proposed resolution

1- Add additional validation to ensure the entered secret name adheres to AWS naming requirements.
2- Update field descriptions for all fields.

Remaining tasks

User interface changes

API changes

Data model changes