Removal of SendingXNotifications in v14

[Matthew-Wise]

I think these notifications have been undervalued and shouldn't be removed in v14. They are quick to make little tweaks to what the back office allows a user to do. In particular SendingContentNotification.

I get the want for Front end/ Back end separation, manipulation the data sent to the front end is really useful. This might be a case of where's my cheese, but would like to at least know why.

discord link - https://discord.com/channels/869656431308189746/1238039395748020275 (will post this link here ofc)

[dawoe]

I just stumbled on this because I am preparing for a upgrade to V14. This will prevent us to do a upgrade.
We use a lot of these notifications in our current V13 project.

Also I think it's very strange this get's removed without any heads up. This is in conflict with Umbraco's own deprication policy :

When we need to remove something from i.e. the public API, we will release a minor version with the deprecation in it, and keep it around for the next major as well (so announced deprecation in 10.2.0 means it will no longer be available in 12.0.0).

See : https://umbraco.com/products/knowledge-center/versioning-and-release-cadence/

Some of the use cases of these events can be found in the code examples of my DF22 talk : https://github.com/dawoe/df22-journey-into-the-unknown/tree/main
But there are more : disabling preview, removing links, setting default property values, making properties readonly.

But what makes it even worse a lot the things removed in this PR (#15855) are still documented.
https://docs.umbraco.com/umbraco-cms/reference/notifications/editormodel-notifications
https://docs.umbraco.com/umbraco-cms/customizing/section-trees/searchable-trees
https://docs.umbraco.com/umbraco-cms/reference/content-delivery-api/additional-preview-environments-support#configuring-custom-preview-urls

And as it seems there is no alternative.