Add support of Interpolated strings.

[yangzhongke]

Add support of Interpolated strings.
see #527

I have added two test cases: QueryableTests.FormattableString.cs and EntitiesTests.FormattableString.cs. All the tests are passed:

[StefH]

Hello @yangzhongke, thank you for your contribution.

However, I thought that this functionality would be integrated in the current code, and not creating new extension methods.

Can you change your PR?

[yangzhongke]

If there are two overloaded methods as below:

1. Where(string predicate,params object[] args)
2. Where(FormattableString predicate)

Due to the deliberate decision by the Microsoft , The code Where($"Id={id}") will invoke Where(string predicate,params object[] args) instead of Where(FormattableString predicate), which lead to my decision to create new method names, like WhereInterpolated instead of using Where.

[StefH]

Can't you just add a new method like?

Existing...

public static IQueryable Where([NotNull] this IQueryable source, [NotNull] ParsingConfig config, [NotNull] string predicate, params object[] args)

New...

public static IQueryable Where([NotNull] this IQueryable source, [NotNull] ParsingConfig config, [NotNull] FormattableString predicate)

[yangzhongke]

I can. But where($" id={id}") will invoke the "string predicate" version instead of "FormattableString" version.
So I have to create the WhereInteroplated(FormattableString fs) method to match WhereInteroplated($" id={id}").
I have mentioned the reason before.
Make sense?

[yangzhongke]

Even EF Core created two methods to execute sql statements, ExecuteSqlRaw(string version) and ExecuteSqlInterpolated(FormatableString version). So I reckon that the two different methods solution, Where and WhereInterpolated , is a tradeoff.

[yangzhongke]

Agree with the renaming.
Should I do something to do the changes?

[StefH]

@yangzhongke
Yes, if possible, change your PR code.

[yangzhongke]

I have renamed those two files and committed the changes.
There are two files: DynamicQueryableWithFormattableStringExtensionsand EFDynamicQueryableWithFormattableStringExtensions.
DynamicQueryableWithFormattableStringExtensions.cs contains: AllInterpolated and other XXXInterpolated methods, and EFDynamicQueryableWithFormattableStringExtensions contains: AllInterpolatedAsync and other XXXInterpolatedAsync methods.
DynamicQueryableWithFormattableStringExtensionsand .cs is already on the src/System.Linq.Dynamic.Core folder; because EFDynamicQueryableWithFormattableStringExtensions uses Microsoft.EntityFrameworkCore, just like EntityFrameworkDynamicQueryableExtensions.cs, so EFDynamicQueryableWithFormattableStringExtensions should be on the folder Microsoft.EntityFrameworkCore.DynamicLinq.EFCore3.