RFR: forge: add HostedRepository.nonTransformedWebUrl

[Erik Helin]

Hi all,

please review this patch that adds the method `HostedRepository.nonTransformedWebUrl`. This will be used in a follow-up
patch to improve the message from the `MergeBot`.

Testing:
- `make test` passes on Linux x64
- Added one new unit test

Thanks,
Erik

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Commit messages:
 - forge: add HostedRepository.nonTransformedWebUrl

Changes: https://git.openjdk.java.net/skara/pull/546/files
 Webrev: https://webrevs.openjdk.java.net/skara/546/webrev.00
  Stats: 37 lines in 7 files changed: 36 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/546.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/546/head:pull/546

PR: https://git.openjdk.java.net/skara/pull/546