Plugins: Add Plugin FS abstraction (#63734)

* unexport pluginDir from dto

* first pass

* tidy

* naming + add mutex

* add dupe checking

* fix func typo

* interface + move logic from renderer

* remote finder

* remote signing

* fix tests

* tidy up

* tidy markdown logic

* split changes

* fix tests

* slim interface down

* fix status code

* tidy exec path func

* fixup

* undo changes

* remove unused func

* remove unused func

* fix goimports

* fetch remotely

* simultaneous support

* fix linter

* use var

* add exception for gosec warning

* fixup

* fix tests

* tidy

* rework cfg pattern

* simplify

* PR feedback

* fix dupe field

* remove g304 nolint

* apply PR feedback

* remove unnecessary gosec nolint

* fix finder loop and update comment

* fix map alloc

* fix test

* remove commented code

pkg/plugins/manager/fakes/fakes.go

@@ -4,6 +4,7 @@ import (
 	"archive/zip"
 	"context"
 	"fmt"
+	"io/fs"
 	"sync"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
@@ -351,6 +352,30 @@ func (f *FakeRoleRegistry) DeclarePluginRoles(_ context.Context, _ string, _ str
 	return f.ExpectedErr
 }
 
+type FakePluginFiles struct {
+	FS fs.FS
+
+	base string
+}
+
+func NewFakePluginFiles(base string) *FakePluginFiles {
+	return &FakePluginFiles{
+		base: base,
+	}
+}
+
+func (f *FakePluginFiles) Open(name string) (fs.File, error) {
+	return f.FS.Open(name)
+}
+
+func (f *FakePluginFiles) Base() string {
+	return f.base
+}
+
+func (f *FakePluginFiles) Files() []string {
+	return []string{}
+}
+
 type FakeSources struct {
 	ListFunc func(_ context.Context) []plugins.PluginSource
 }