cpp_info.components first iteration

[danimtb]

Changelog: Feature: Add cpp_info.components package creator interface to model internal dependencies inside a recipe.
Docs: conan-io/docs#1363

This PR covers the following:

• cpp_info.components to define different "targets" at recipe creator level
• deps_cpp_info.components is not available, all the info can be only consumed in a "global" or per dependency way taking into account the new info introduced by each component.
• dependency among components is not modeled yet. Components are iterated in insertion order.
• Components cannot be defined inside components (as said above, dependency among components will be implemented in a separate PR)
• Components cannot be defined per configuration. This means no cpp_info.release.components["name"].... is allowed. This has been left for future consideration.

Additional points after review:

• Components have default directory values when created: includedirs, bindirs, libdirs...
• Mixing Components and "global" values is not allowed in the same recipe.
• Components DO filter paths (same behavior as cpp_info).

---

• Refer to the issue that supports this Pull Request: closes #5090, closes #2387
• If the issue has missing info, explain the purpose/use case/pain/need that covers this Pull Request.
• I've read the Contributing guide.
• I've followed the PEP8 style guides for Python code.
• I've opened another PR in the Conan docs repo to the develop branch, documenting this one.

^{Note: By default this PR will skip the slower tests and will use a limited set of python versions. Check here how to increase the testing level by writing some tags in the current PR body text.}

[jgsogo]

I like what I see 🙌 just really quick comments, don't take them seriously.

[memsharded]

Looking good!
Please have a look to the comments.

[jgsogo]

Good! Let's see if we can tackle those two comments. Thanks!

[jgsogo]

💪 Great!

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Docs needed

[danimtb]

Added docs at conan-io/docs#1363

[uilianries]

we have components!