[http-server-csharp] multi-line comments aren't handled well by model generation

[jovinson-ms]

Describe the bug

Given a TypeSpec model like:

  @maxLength(16)
  @minLength(1)
  @doc("""
    Format of the redacted output. Only valid when Operation is Redact. 
    Please refer to https://learn.microsoft.com/en-us/azure/healthcare-apis/deidentification/redaction-format for more details.
    """)
  redactionFormat?: string;

the generated model looks like:

        ///<summary>
        /// Format of the redacted output. Only valid when Operation is Redact.  Please
        /// Format of the redacted outpu
        /// Format of the redacted output. Only valid when Operation is Redact.  P
        /// ils.
        ///</summary>
        [TypeSpec.Helpers.JsonConverters.StringConstraint(MinLength = 1, MaxLength = 16)]
        public string RedactionFormat { get; set; }

Reproduction

Can't be reproduced in Playground

Checklist

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• The provided reproduction is a minimal reproducible example of the bug.