sfml: conan v2 support

[SpaceIm]

Specify library name and version: lib/1.0

This is also a good place to share with all of us why you are submitting this PR (specially if it is a new addition to ConanCenter): is it a dependency of other libraries you want to package? Are you the author of the library? Thanks!

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• I've read the guidelines for contributing.
• I've followed the PEP8 style guides for Python code in the recipes.
• I've used the latest Conan client version.
• I've tried at least one configuration locally with the conan-center hook activated.

[conan-center-bot]

All green in build 2 (27e9f22e045d794c990ee86d0779cfbd18aec161):

• sfml/2.5.1@:
  All packages built successfully! (All logs)

[github-actions]

Hooks produced the following warnings for commit 27e9f22

sfml/2.5.1

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libsfml-window.2.5.1.dylib' links to system library 'CoreServices' but it is not in cpp_info.frameworks.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libsfml-window.dylib' links to system library 'CoreServices' but it is not in cpp_info.frameworks.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libsfml-window.2.5.dylib' links to system library 'CoreServices' but it is not in cpp_info.frameworks.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libsfml-window-d.2.5.dylib' links to system library 'CoreServices' but it is not in cpp_info.frameworks.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libsfml-window-d.2.5.1.dylib' links to system library 'CoreServices' but it is not in cpp_info.frameworks.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libsfml-window-d.dylib' links to system library 'CoreServices' but it is not in cpp_info.frameworks.