Plugins: Make it possible to support multiple plugin versions (#82116)

* first pass

* use version in more places

* add comment

* update installer

* fix wire

* fix tests

* tidy

* simplify changes

* fix in mem

* remove unused step

* fix step dupe logic for child plugins + add tests

pkg/plugins/manager/pipeline/discovery/steps.go

@@ -6,9 +6,7 @@ import (
 
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/plugins/config"
-	"github.com/grafana/grafana/pkg/plugins/log"
 	"github.com/grafana/grafana/pkg/plugins/manager/loader/finder"
-	"github.com/grafana/grafana/pkg/plugins/manager/registry"
 )
 
 // DefaultFindFunc is the default function used for the Find step of the Discovery stage. It will scan the local
@@ -17,44 +15,6 @@ func DefaultFindFunc(cfg *config.Cfg) FindFunc {
 	return finder.NewLocalFinder(cfg.DevMode, cfg.Features).Find
 }
 
-// DuplicatePluginValidation is a filter step that will filter out any plugins that are already registered with the
-// registry. This includes both the primary plugin and any child plugins, which are matched using the plugin ID field.
-type DuplicatePluginValidation struct {
-	registry registry.Service
-	log      log.Logger
-}
-
-// NewDuplicatePluginFilterStep returns a new DuplicatePluginValidation.
-func NewDuplicatePluginFilterStep(registry registry.Service) *DuplicatePluginValidation {
-	return &DuplicatePluginValidation{
-		registry: registry,
-		log:      log.New("plugins.dedupe"),
-	}
-}
-
-// Filter will filter out any plugins that are already registered with the registry.
-func (d *DuplicatePluginValidation) Filter(ctx context.Context, bundles []*plugins.FoundBundle) ([]*plugins.FoundBundle, error) {
-	res := make([]*plugins.FoundBundle, 0, len(bundles))
-	for _, b := range bundles {
-		_, exists := d.registry.Plugin(ctx, b.Primary.JSONData.ID)
-		if exists {
-			d.log.Warn("Skipping loading of plugin as it's a duplicate", "pluginId", b.Primary.JSONData.ID)
-			continue
-		}
-
-		for _, child := range b.Children {
-			_, exists = d.registry.Plugin(ctx, child.JSONData.ID)
-			if exists {
-				d.log.Warn("Skipping loading of child plugin as it's a duplicate", "pluginId", child.JSONData.ID)
-				continue
-			}
-		}
-		res = append(res, b)
-	}
-
-	return res, nil
-}
-
 // PermittedPluginTypesFilter is a filter step that will filter out any plugins that are not of a permitted type.
 type PermittedPluginTypesFilter struct {
 	permittedTypes []plugins.Type