Fix for ISO string modification during function metadata binding parsing

[satvu]

Issue describing the changes in this PR

resolves #10732 (and Azure/azure-functions-dotnet-worker#2882)

Pull request checklist

IMPORTANT: Currently, changes must be backported to the in-proc branch to be included in Core Tools and non-Flex deployments.

• Backporting to the in-proc branch is not required
  • Otherwise: Link to backporting PR
• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
• My changes do not need to be backported to a previous version
  • [] Otherwise: Backport tracked by issue/PR #issue_or_pr
• My changes do not require diagnostic events changes
  • Otherwise: I have added/updated all related diagnostic events and their documentation (Documentation issue linked to PR)
• I have added all required tests (Unit tests, E2E tests)

Additional information

Tested locally E2E the following scenarios:

1. StartFromTime set to a past time started triggering and processing existing records immediately after startup (older records than start time untouched)
2. StartFromTime set to a future date and will process any new changes following startup. Discussed with original engineers - this feature was only meant to go into the past, so there was never a design set for future dates. This setting will not ignore changes until that future date (note: need to test InProc to see if behavior is the same there).

[satvu]

Discussed offline with @liliankasem - to incorporate suggestions we will need to refactor ValidateBindings (see here) and change it from a static method. Investigation shows that the only places where this method is called is in tests and within the same class. This should be a safe change.

[liliankasem]

I don't love this class. The name is really vague. Could you create a folder called Serializers and have a file with both of these classes in it?

Also do the settings need to be their own separate class?

how about something like this?

using Newtonsoft.Json;

namespace Microsoft.Azure.WebJobs.Script.Serialization
{
    /// <summary>
    /// Provides shared JSON serialization settings and serializers.
    /// </summary>
    internal static class JsonSerialization
    {
        /// <summary>
        /// JSON serializer settings with no date parsing.
        /// </summary>
        public static readonly JsonSerializerSettings NoDateParsingSettings = new JsonSerializerSettings
        {
            DateParseHandling = DateParseHandling.None
        };

        /// <summary>
        /// JSON serializer instance configured with no date parsing settings.
        /// </summary>
        public static readonly JsonSerializer NoDateParsingSerializer =
            JsonSerializer.Create(NoDateParsingSettings);
    }
}

[liliankasem]

Second I am concerned about the thread safety of this, and testability?

Is there a second we didn't go with DI for this?

[liliankasem]

I think the file needs to be deleted?