drupal_check_incompatibility() should be moved to a VersionChecker class

Problem/Motivation

The module handler includes a parseDependency() method that converts a module version string into an array format expected by the closely related drupal_check_incompatibility(), which is a global function but depends on this expected format.

Proposed resolution

Introduce a new VersionChecker helper class which can parse dependencies and check them for incompabilities ...

Remaining tasks

User interface changes

N/A.

API changes

\Drupal\Core\Extension\VersionChecker added.

Data model changes

None.