Feature: Add support for querying a IQueryable<dynamic>

[NickDarvey]

Updates the ParseMemberAccess method so that if it can't get the property or field, it tries getting the member by a dynamic operation or by an indexer operation.

After a lot of searching I ended up on this bit of code which seems to do the trick. The ExpressionTests_Select_ExpandoObjects test passes now.

Some notes:

• It will throw an exception only during evaluation if it can't find the specified member (and it is an object or has an indexer), currently a InvalidOperationException but perhaps introducing a new exception type is warranted?
• I'd still like to get ExpressionTests_Select_DynamicObjects but I'm not sure how I'll go.
• @StefH: Are you able to pull this and run all the tests on your machine? I was only able to get the solution building with a lot of hacking of projects and stripping out all platforms except net461.

[NickDarvey]

Sweet CI! Okay, will take a look at which platform is dying...

[NickDarvey]

Oh, also tagging #136

[NickDarvey]

Ah, okay, it's failing to build System.Linq.Dynamic.Core.Tests.csproj because System.Linq.Expressions.Expression.Dynamic Method (CallSiteBinder, Type, IEnumerable<Expression>) is not available in netcoreapp1.1

What do you think about changing the test project to target netcoreapp2.0 (which has the method is available) and make this feature conditional and only available for netstandard2.0 platforms?
(Here's the method in the .NET API Browser.)

[StefH]

I'll take your PR and take a look.

[codecov]

Codecov Report

Merging #137 into master will decrease coverage by 0.4%.
The diff coverage is 38.46%.

@@            Coverage Diff             @@
##           master     #137      +/-   ##
==========================================
- Coverage   82.95%   82.54%   -0.41%     
==========================================
  Files          35       36       +1     
  Lines        3484     3512      +28     
  Branches      486      487       +1     
==========================================
+ Hits         2890     2899       +9     
- Misses        455      481      +26     
+ Partials      139      132       -7

Impacted Files	Coverage Δ
src/System.Linq.Dynamic.Core/DynamicClass.cs	7.69% <0%> (-1.24%)	⬇️
...System.Linq.Dynamic.Core/DynamicGetMemberBinder.cs	0% <0%> (ø)
...em.Linq.Dynamic.Core/DynamicQueryableExtensions.cs	98.3% <100%> (+0.01%)	⬆️
...ystem.Linq.Dynamic.Core/Parser/ExpressionParser.cs	77.43% <52.17%> (-0.27%)	⬇️
src/System.Linq.Dynamic.Core/Parser/TypeHelper.cs	88.2% <0%> (+0.47%)	⬆️
...c/System.Linq.Dynamic.Core/Tokenizer/TextParser.cs	98.03% <0%> (+1.3%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a0c358a...879ed96. Read the comment docs.

[NickDarvey]

Alright, ExpressionTests_Select_DynamicObjects might need to come in another PR... Can this get merged in without it?

[StefH]

I will merge this code (at this point) to main and create a new NuGet. The discussion on other possible solutions will be done into the issue #136.