[BUG] Enhance Input Validation for UpdateModel and UpdateModelGroup APIs

[rithin-pullela-aws]

What is the bug?
The 2 APIs have potential vulnerability: UpdateModel and UpdateModelGroup

Currently, these APIs accept script-like variables in their request bodies without raising exceptions, which could potentially lead to security risks.

Impact: This vulnerability could potentially be exploited to inject malicious scripts, posing a risk to the system's integrity and security.

How can one reproduce the bug?
Steps to reproduce the behavior:

• Create a model or a model group
• Make this API Call:

PUT /_plugins/_ml/models/w2jYiJUBIo18BRbyKFkp
{
  "name": "<script>alert(1)</script>",
  "description": "<script>alert(1)</script>"
}

• Observe a successful update.

What is the expected behavior?
Apply stricter regex matching to validate inputs

What is your host/environment?

• OS: [e.g. iOS]
• Version [e.g. 22]
• Plugins

Do you have any screenshots?
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Do you have any additional context?
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