Remove ResourceController mappigs with param useDefaultLabel

[spencergibb]

ResourceController has multiple @RequestMappings that would conflict, currently to avoid passing the label we use the useDefaultLabel request parameter to select. Starting with spring 5.3 this is no longer happening.

Given

	@RequestMapping("/{name}/{profile}/{label}/**")
// and 
	@RequestMapping(value = "/{name}/{profile}/**", params = "useDefaultLabel")

Calling /foo/default/file.txt?useDefaultLabel used to route to the later, now it routes to the former and produces an error because the file is treated as a label.

[spencergibb]

After writing some samples, it appears that using the useDefaultLabel request parameter to select a different @RequestMapping hasn't worked for some time. It appears that no one is using this as no one is reporting problems. This method will get removed instead.

[dinhani]

I was starting to use the the ResourceController for serving plain-text files, but it did not work.
Is the support for plain-text files being removed or just migrated to something else?

[spencergibb]

@dinhani no, this is to remove specific use of a query parameter named useDefaultLabel that doesn't work anyway.

[ThomasVitale]

@spencergibb can I help with this task?

[spencergibb]

@ThomasVitale sure

[ThomasVitale]

@spencergibb I've just created a PR: #1728
I've removed both mappings in ResourceController using the useDefaultLabel. Is it ok?