Reimplement Matcher with plugin instances support

[mirodietiker]

The Matchers currently don't support instances and all forms just work for the default instances.

This needs a proper port to D8 plugin concept.

[mbovan]

I pushed changes that I made in the feature branch (feature/crm-core-arch-changes):
Diff with CRM Core 8.x-0.x branch.

Here are the patches to apply on Collect and Inmail so it's easier to manually test changes by enabling collect_demo:

• Collect patch
• Inmail patch

I'll try to summary changes from local commit messages:

• MatchingRule from crm_core_default_matching_engine becomes Matcher config entity in crm_core_match module
• MatchEngineBase inherits PluginBase, MatchEngineInterface extends PluginInspectionInterface and PluginFormInterface
• DefaultMatchingEngine becomes plugin (plugin_id property) of a Matcher
• Removed unused routes, changed existing to follow D8 standards
• MatcherListBuilder to show all created matchers.
• Forms for adding/editing/deleting a Matcher.
• Implemented dynamic schema for plugins (match engines).
• Due to new changes, matcher settings doesn't support selection of the fields per contact type bundle. Instead, fields from all bundles are displayed. (We agreed that this should be a follow-up)
• Removed status property from a Matcher - no use case for it.
• Several UI changes, matcher overview, matcher edit form (removed empty operator option for field matching selection)
• Added some todos for hard-coded matcher calls (EventSubscriber and ContactMatcher in Collect)

There is some commented-out (Drupal 7?) code (e.g. in crm_core_match.test.inc) we should decide what to do with. Seems that crm_core_match\Matcher and crm_core_match\MatcherInterface are not used anymore but I didn't delete them as there are some methods that maybe we should move/implement to/in other classes.

Regarding tests, I didn't run any automatic test (tested manually), I guess there are lot of fails, especially for Unit/kernel tests, but the purpose of the first patch is to show an idea where we want to be at the end. :)

Waiting for review... @mirodietiker, @Berdir

Screenshot of Matchers overview page

The form for adding a new matcher

[mirodietiker]

Committed a followup from the plubin instances for collect integration: #21

Can we still close this issue or leave it open until #17 is fixed?