Add plugin release Update Manager Client

[xxsimoxx]

All Submissions:

• Have you followed the Classic Commerce Contributing guideline?
• Does your code follow the repo standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

1. Update the Update client to latest version (Last modified on Update Manager release: 2.4.0).
2. Added filters that points to the right location of images.
3. Added filter to handle plugin usage statistics privacy opt-out.

Closes #211 .

Maybe (that is not already added) we should limit the download of a new version from this repo?

[xxsimoxx]

We should check #300 and #301, where the update server is changed and this comment.
Is it https://officialplugins.classicpress.net/ or https://officialplugins.classicpress.net/?

[ghost]

Actually I am not sure. The Update Manager is still loaded onto classiccommerce.cc and it used to be where updates got pushed from. It even has the latest version showing as if it has been used for that. But the client file does have const UPDATE_SERVER = 'https://officialplugins.classicpress.net/';.

So I guess that is now where the UM lives. My mistake. Ignore previous comment.

[xxsimoxx]

So I guess that is now where the UM lives.

Update Manager lives at classiccommerce.cc but since 1.0.4 the clients look at officialplugins.classicpress.net.

officialplugins.classicpress.net subdomain does not exists but must be online before any update can be pushed.
Then a decision can be taken about where to serve pudate from.

[ClassyBot]

This pull request has been mentioned on ClassicPress Forums. There might be relevant details there:

https://forums.classicpress.net/t/update-servers/3622/1

[ghost]

We still need to clarify where the updates are pushed from. At some point the CC site moved from my hosting to CP servers and things were rearranged, but I have no idea about the current arrangement. The Update Manager is still active on the CC site, but as Simone says:

since 1.0.4 the clients look at officialplugins.classicpress.net.

[bahiirwa]

Maybe we need to put this on hold as we make patches to catch up with some security stuff with WC. This will give us time to evaluate on whether to use the new directory.

[xxsimoxx]

Agree with you to put on hold:

• the UpdateClient in this PR is outdated.
• officialplugins.classicpress.net does not exists.
  We can refactor this PR if we decide to serve updates with Update Manager, but having the new directory I don't think this will be the case.