adding support to 'plugin' package

[Raiane-Dev]

for cases where we have package import errors, it is good to have the option to link a plugin that contains these libraries.

[CLAassistant]

All committers have signed the CLA.

[mvertes]

Thank you for this first contribution! In fact, to add a new generated wrapper, you need to do the following:

• edit the file listing the wrappers to be generated, and add the missing plugin name to it, for example at

  yaegi/stdlib/stdlib.go

  Line 54 in c32b3ec

  //go:generate ../internal/cmd/extract/extract path path/filepath reflect regexp regexp/syntax

• from project root, run make generate with go version go1.22
• make generate again with go version go1.21

You should obtain new generated files stdlib/go1_21_plugin.go and stdlib/go1_22_plugin.go.

The pull request should contain patches to stdlib/stdlib.go, and the generated files.

Thanks.