Make code generator include external references for finding binding c…

…ontexts

Merge branch 'development'

Merge pull request #242 from marcin-golebiowski/IsValid

Add back Export.IsValid property

Merge pull request #241 from SpiceSharp/development

Fix yield flags and write tests, found by Marcin

Merge pull request #240 from SpiceSharp/development

Development

Update publish-nuget.yml

Merge pull request #229 from SpiceSharp/development

Update version

Merge pull request #221 from SpiceSharp/development

v3.1.8

Merge pull request #214 from SpiceSharp/development

Development

Merge pull request #212 from SpiceSharp/development

v3.1.6