Encoded purl components as per the PURL specification. (#23)

* Encoded Version, subpath, name, qualifier components of a PURL as per PURL specifation.

* Addressed Pr comments.

* Addressed PR comments.

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Co-authored-by: Mounika Rendedla <morended@microsoft.com>

Fix issues handling golang packages with multi-part namespaces. (#20)

* Fix issues handling golang packages with multi-part namespaces.
Added a test for it as well.

* Update src/PackageUrl.cs

Match packageurl-js implementation for namespace encoding.

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

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Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

Standardize namespace and name normalization to match Python library (#…

…22)

* Standardize namespace and name normalization to match Python library

* Add github example to test data

Prevent lowercasing npm names to support grandfathered packages (#19)

npm used to support package names
containing capital characters:
https://blog.npmjs.org/post/168978377570/new-package-moniker-rules.html

Such packages still exist on the npm
registry, like this one:
https://www.npmjs.com/package/Acid/v/3.0.17

cocoapods, cran, vsm and cpan packages should not be lowered (#18)

* Dont lower cocoa, cpan, vsm and cran package names

Cocoapods, CPAN, VSM and CRAN package managers are case sensitive and need the original name string - when the name is automatically lowered you cannot find the packages in the responsitory.

* Update PackageUrl.cs

* Update PackageUrl.cs

Some managers also have case sensitive namespaces

* Remove static from ValidateNamespace

* Update PackageUrl.cs

* Fix namespace switch

* Add missing semicolon.

* Per discussion. Remove all lowering and replace

Removes the ToLower and the Replace methods which were modifying the ValidateName and ValidateNamespace methods.

* Revert "Per discussion. Remove all lowering and replace"

This reverts commit aa1a107.

* Add Tests

* Update src/PackageUrl.cs

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

* Update PackageUrl.cs

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

Merge pull request #13 from ThomasPiskol/master

Change package ID to "packageurl-dotnet"