PluginTypeManager::getPluginTypes() requires config schema, slows down installation

Unrelated test fail but easy to fix, so adding that as well.

Lets assume you have an install profile with 100 modules:

1-25. [ .. 25 modules first.... ]
26. plugin is installed
27. currency is installed
28. some other module is installed
29. payment is installed.
30-100. all the other modules.

What happens right now is that step 26 gets all plugin_type yml files, which then is just plugin and creates definition objects, for which it needs the config schema, so that is parsed. On step 27, we re-parse them and get plugin and currency (only currency is actually read from the file system because that is apcu cached), then we create definition objects for plugin (again) and currency (new). the yaml cache only caches the raw parsed yaml. On step 28, we do the same as in step 27, even though nothing is new. On step 29, we also parse and create objects for payment, additionally to plugin and currency. And then we do another 70 times, the same for every single module. And all of them need to do a config schema discovery*.

With my patch, we no longer cache the raw content of the plugin_type files, we cache the resulting definition objects. For step 26, nothing changes except we cache differently. For step 26, we already have all the definition objects defined in plugin and just load them from apcu, but we also have the new currency types, so we still do a config schema discovery. But on step 28, we can load everything from cache, no config schema discovery necessary. On step 29, we need it again for the new payment types. But step 30-100 then again doesn't need it, we just need to check for new plugin type files but we don't find any that aren't already cached.

Does this help?

Leaving at needs review since this is mostly just opinion based suggestions, nothing that must be changed. But since we change the code anyway...

1. +++ b/src/PluginType/PluginTypeManager.php
   @@ -71,32 +80,84 @@ class PluginTypeManager implements PluginTypeManagerInterface {
   +    $file_cache = FileCacheFactory::get('plugin:' . $this->name);
   

   Note that I copied $this->name from YamlDiscovery because I was lazy. Feel free to use a better name or simply hardcode it in the handful of places that actually need it.

2. +++ b/src/PluginType/PluginTypeManager.php
   @@ -71,32 +80,84 @@ class PluginTypeManager implements PluginTypeManagerInterface {
   +    foreach ($file_cache->getMultiple($files) as $file => $data) {
   +      $this->pluginTypes = array_merge($this->pluginTypes, $data);
   

   maybe use a better variable name for $data?

3. +++ b/src/PluginType/PluginTypeManager.php
   @@ -71,32 +80,84 @@ class PluginTypeManager implements PluginTypeManagerInterface {
   +      $plugin_type_definition_defaults = [
   +        'class' => PluginType::class,
   +        'provider' => $provider,
   +      ];
   

   this is a two-line array that is defined on every loop and then has to be use'd for the anonymous function.

   What about putting it inside as you only use it there or actually just drop the variable. You already set the ID as well, you could convert this to a single $plugin_type_definition += [
   'id' => $plugin_type_id,
   'class' => ..

   and so on? (not 100% sure right now if the id is overriding something, then you need to keep it but I think not and why would you specify something else than your own id?.

As discussed, you made a valid argument why the defaults are outside, makes sense to me.