[FEATURE] Unable to use Term Query for Enums

[DR9885]

Is your feature request related to a problem? Please describe.

Would like to be able to this with client, like in NEST client.

    public class TestModel
    {
        public string Id { get; set; }
        public TestEnum Enum { get; set; }
    }

    public enum TestEnum
    {
        Unknown,
        First,
        Second
    }

    var res = await _elasticsearchClient.SearchAsync<TestModel>(s => s
        .Index("test")
        .Query(q => q
            .Bool(b => b
                .Must(m => m
                    .Terms(ts => ts.Field(f => f.TestEnum).Terms(new [] { TestEnum.Unknown }))
                )
            )
        )
    ); 

Ref: (similar)
#7716

Describe the solution you'd like
filter on enums

Describe alternatives you've considered
Event this didn't work...

    var enumFieldValues = models.Select(x => x.Enum).Select(x => FieldValue.String(x.ToString())).ToArray();
    var res = await _repo.FindAllAsync<TestModel>(s => s
        .Index(_index)
        .Size(ids.Length)
        .Query(q =>
            q.Bool(b =>
                b.Filter(
                    f => f.Terms(x => x.Field(ff => ff.Enum).Terms(new TermsQueryField(enumFieldValues)))
                )
        )),
    CancellationToken.None);

[DR9885]

found workaround:

    var enumFieldValues = models.Select(x => x.Enum).Select(x => FieldValue.String(x.ToString())).ToArray();
    var res = await _repo.FindAllAsync<TestModel>(s => s
        .Index(_index)
        .Size(ids.Length)
        .Query(q =>
            q.Bool(b =>
                b.Filter(
                    f => f.Terms(x => x.Field("enum.keyword").Terms(new TermsQueryField(enumFieldValues)))
                )
        )),
    CancellationToken.None);