[MM-14576] Add GetBundlePath method to Plugin API (#10466)

* Fix typo

* Add GetBundlePath method to Plugin API

* Change signature to GetBundlePath() (string, error)

* Add test

app/plugin_api.go

@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"path/filepath"
 	"strings"
 
 	"github.com/mattermost/mattermost-server/mlog"
@@ -98,6 +99,15 @@ func (api *PluginAPI) SavePluginConfig(pluginConfig map[string]interface{}) *mod
 	return api.app.SaveConfig(cfg, true)
 }
 
+func (api *PluginAPI) GetBundlePath() (string, error) {
+	bundlePath, err := filepath.Abs(filepath.Join(*api.GetConfig().PluginSettings.Directory, api.manifest.Id))
+	if err != nil {
+		return "", err
+	}
+
+	return bundlePath, err
+}
+
 func (api *PluginAPI) GetLicense() *model.License {
 	return api.app.License()
 }