Support System.Text.Json

[niemyjski]

Currently users of this library using System.Text.Json (STJ) cannot return search aggregation results (from redis cache, or from api endpoints) due to serialization dependencies on Newtonsoft.Json. Our goal is to update the Foundatio.Repositories to work with System.Text.Json. However, we don’t want to break other applications so we need to support Newtonsoft.Json by leaving the existing JsonConverters in place unless we can find a way to support both out of the box without the dependency or an easy way for it to be configured externally.

I see this happening in the following steps:

1. Copy the following code snippet to end of AggregationQueryTests.GetTermAggregationsWithTopHitsAsync().

            string systemTextJson = System.Text.Json.JsonSerializer.Serialize(result);
            Assert.Equal(json, systemTextJson);
            roundTripped = System.Text.Json.JsonSerializer.Deserialize<CountResult>(systemTextJson);
            Assert.Equal(10, roundTripped.Total);
            Assert.Equal(1, roundTripped.Aggregations.Count);
            Assert.Equal(10, roundTripped.Aggregations.Terms<int>("terms_age").Buckets.Count);
            bucket = roundTripped.Aggregations.Terms<int>("terms_age").Buckets.First(f => f.Key == 19);
            Assert.Equal(1, bucket.Total);

2. Add custom converter to handle writing polymorphic json. The nest team is doing something like this: https://github.com/elastic/elasticsearch-net/blob/main/src/Elastic.Clients.Elasticsearch/_Generated/Types/Aggregations/TermsAggregation.g.cs#L27 for one of there aggretaions. I think you'd pass this converter in options of the first call to Serialize in the snippet above. This will solve the first assert.
3. You'd need to add and convert the existing JsonConverters in the Foundatio.Repositories.Utility to System.Text.Json and then add the json converter attributes next to the existing converter attributes. This will fix the round trip part of reading the json text.
4. Request PR Review

Not sure if this link will help on the converters: https://bengribaudo.com/blog/2022/02/22/6569/recursive-polymorphic-deserialization-with-system-text-json

[ejsmith]

I removed some usages of JSON.NET down to where our only usage is pretty much the JSON patch support.

Spent some time taking a look at json-everything's JsonPatch support and it only uses JSON Pointers for paths and does not support some of the things we are doing where we are allowing full JSON Path support where we can do things like $.books[?(@.author == 'John Steinbeck')] to remove all array elements from the books array that has an author sub-property that matches John Steinbeck. So basically we would need to make major changes to their libraries or talk them into supporting JSON Path expressions even though the unofficial JSON Patch spec only supports JSON Pointer.

[ejsmith]

Found this issue where someone asked him and he said no to supporting JSON Path.

[niemyjski]

Comment for previous history:

For Json Patching it would be nice to see if we can get it to work without a dependency or we can internalize the dependency. I see several spots doing patching

• https://github.com/gregsdennis/json-everything
• https://github.com/ladeak/JsonMergePatch
• .NET 7 is adding patching to System.Net.Http.Json, we could see how they did it and perhaps do it here.

[niemyjski]

Initial support for STJ was added in #97 We still need to support Patching