Allow specifying a custom output for the deployers

[AbrilRBS]

Changelog: Feature: Allow to specify a custom deployer output folder.
Docs: conan-io/docs#3275

Closes #13728

[memsharded]

Looks good!
I'd say we can include this in 2.0.5

[memsharded]

Regarding the "development re-locatable Conan-agnostic" deploys feature conan-io/examples2#94, this could be a useful use case:

• it allows to do multiple conan install, different configurations, like linux/windows, or different compilers or architectures will require a different --output-folder or defined build_folder_vars to not overwrite each other
• But it is not intended that every one will contain its own full_deploy copy, because for example tool_requires for the build system for a given cmake.exe, could contain multiple copies. An extra argument to redefine the full_deploy root folder could solve this.

[CLAassistant]

All committers have signed the CLA.

[AbrilRBS]

Picking this back up, the PR felth thru the cracks last month