[MM-64686] Expose audit logging functionality via plugin API (#31204)

This commit exposes audit logging functionality to plugins via the plugin API, allowing plugins to create and log audit records. Additionally, it addresses a gob encoding issue that could cause plugin crashes when audit data contains nil pointers or unregistered types.

server/channels/api4/license.go

@@ -15,7 +15,6 @@ import (
 
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/v8/channels/app"
-	"github.com/mattermost/mattermost/server/v8/channels/audit"
 )
 
 func (api *API) InitLicense() {
@@ -54,7 +53,7 @@ func getClientLicense(c *Context, w http.ResponseWriter, r *http.Request) {
 }
 
 func addLicense(c *Context, w http.ResponseWriter, r *http.Request) {
-	auditRec := c.MakeAuditRecord("addLicense", audit.Fail)
+	auditRec := c.MakeAuditRecord("addLicense", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 	c.LogAudit("attempt")
 
@@ -83,7 +82,7 @@ func addLicense(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	fileData := fileArray[0]
-	audit.AddEventParameter(auditRec, "filename", fileData.Filename)
+	model.AddEventParameterToAuditRec(auditRec, "filename", fileData.Filename)
 
 	file, err := fileData.Open()
 	if err != nil {
@@ -156,7 +155,7 @@ func addLicense(c *Context, w http.ResponseWriter, r *http.Request) {
 }
 
 func removeLicense(c *Context, w http.ResponseWriter, r *http.Request) {
-	auditRec := c.MakeAuditRecord("removeLicense", audit.Fail)
+	auditRec := c.MakeAuditRecord("removeLicense", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 	c.LogAudit("attempt")
 
@@ -177,7 +176,7 @@ func removeLicense(c *Context, w http.ResponseWriter, r *http.Request) {
 }
 
 func requestTrialLicense(c *Context, w http.ResponseWriter, r *http.Request) {
-	auditRec := c.MakeAuditRecord("requestTrialLicense", audit.Fail)
+	auditRec := c.MakeAuditRecord("requestTrialLicense", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 	c.LogAudit("attempt")