Commas in version-ranges make input invalid (breaking)

[jgsogo]

I'm trying things here (https://semver.npmjs.com/) and in fact, commas are never used (we remove them in our code). Anyway, we should keep the possibility of having one comma (it is documented), but remove it for Conan 2.0.

For <2.0, it would be enough to remove those commas from the documentation: https://docs.conan.io/en/latest/mastering/version_ranges.html

Originally posted by @jgsogo in #3898

[jgsogo]

Without commas, the string within the [...] will be the straightforward input to node-semver package (take into account, the proposed options strict/loose and include_prerelease in #3898).

Are you agree with it, @conan-io/barbarians?

1. Remove from docs those commas
2. Remove in Conan 2.0 the replacement of commas by blanks

[memsharded]

Yes, remove them as soon as possible from the docs.

Then, introduce a deprecation warning, telling users to remove comas.

[climblinne]

Updated documentation by removing commas.

[climblinne]

Look into 13defc0. Would this message be fine?

[jgsogo]

Version ranges with commas will be invalid in v2.0 and will throw an exception.

[memsharded]

Version ranges in develop2 no longer use comma to separate conditions (they still use commas to separate the include-prerelease part)