v14: Remove mentions of UmbracoApiController

[Zeegaan]

Notes

• Removes UmbracoApiController, UmbracoApiControllerBase & UmbracoApiControllerAttribute classes, and mention of those.
• This is because this pattern is no longer used at all, and is instead replace with the UmbracoManagementApiControllerBase instead.

How to test

• The solution should build, and the backoffice should work as is.
• Create a document type named "Root" with allow as root set to true.
• Create a template also called "Root"
• Go to your document type, and be sure to select the template you just created.
• Create some content with the document type, again ensure the template on the content is correct.
• Go to the / route and assert you content is rendered 👍

[Migaroez]

Looks good and nothing seems to break.

Is there a linked task to prep the v14 CMS docs for this change? Implementors are very used to simply inheriting from UmbracoApiController and have it auto routed to /umbraco/api and not have to deal with adding it to the reserved paths list.

see https://docs.umbraco.com/umbraco-cms/implementation/controllers#umbraco-api-controllers and https://docs.umbraco.com/umbraco-cms/reference/routing/umbraco-api-controllers

[Zeegaan]

No but good point, I will make sure there is a task covering this change 😁