[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/saml.go

@@ -12,7 +12,6 @@ import (
 
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
-	"github.com/mattermost/mattermost/server/v8/channels/audit"
 )
 
 func (api *API) InitSaml() {
@@ -83,9 +82,9 @@ func addSamlPublicCertificate(c *Context, w http.ResponseWriter, r *http.Request
 		return
 	}
 
-	auditRec := c.MakeAuditRecord("addSamlPublicCertificate", audit.Fail)
+	auditRec := c.MakeAuditRecord("addSamlPublicCertificate", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
-	audit.AddEventParameter(auditRec, "filename", fileData.Filename)
+	model.AddEventParameterToAuditRec(auditRec, "filename", fileData.Filename)
 
 	if err := c.App.AddSamlPublicCertificate(fileData); err != nil {
 		c.Err = err
@@ -107,9 +106,9 @@ func addSamlPrivateCertificate(c *Context, w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	auditRec := c.MakeAuditRecord("addSamlPrivateCertificate", audit.Fail)
+	auditRec := c.MakeAuditRecord("addSamlPrivateCertificate", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
-	audit.AddEventParameter(auditRec, "filename", fileData.Filename)
+	model.AddEventParameterToAuditRec(auditRec, "filename", fileData.Filename)
 
 	if err := c.App.AddSamlPrivateCertificate(fileData); err != nil {
 		c.Err = err
@@ -136,7 +135,7 @@ func addSamlIdpCertificate(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	auditRec := c.MakeAuditRecord("addSamlIdpCertificate", audit.Fail)
+	auditRec := c.MakeAuditRecord("addSamlIdpCertificate", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 	auditRec.AddMeta("type", d)
 
@@ -157,7 +156,7 @@ func addSamlIdpCertificate(c *Context, w http.ResponseWriter, r *http.Request) {
 			c.Err = err
 			return
 		}
-		audit.AddEventParameter(auditRec, "filename", fileData.Filename)
+		model.AddEventParameterToAuditRec(auditRec, "filename", fileData.Filename)
 
 		if err := c.App.AddSamlIdpCertificate(fileData); err != nil {
 			c.Err = err
@@ -178,7 +177,7 @@ func removeSamlPublicCertificate(c *Context, w http.ResponseWriter, r *http.Requ
 		return
 	}
 
-	auditRec := c.MakeAuditRecord("removeSamlPublicCertificate", audit.Fail)
+	auditRec := c.MakeAuditRecord("removeSamlPublicCertificate", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 
 	if err := c.App.RemoveSamlPublicCertificate(); err != nil {
@@ -196,7 +195,7 @@ func removeSamlPrivateCertificate(c *Context, w http.ResponseWriter, r *http.Req
 		return
 	}
 
-	auditRec := c.MakeAuditRecord("removeSamlPrivateCertificate", audit.Fail)
+	auditRec := c.MakeAuditRecord("removeSamlPrivateCertificate", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 
 	if err := c.App.RemoveSamlPrivateCertificate(); err != nil {
@@ -214,7 +213,7 @@ func removeSamlIdpCertificate(c *Context, w http.ResponseWriter, r *http.Request
 		return
 	}
 
-	auditRec := c.MakeAuditRecord("removeSamlIdpCertificate", audit.Fail)
+	auditRec := c.MakeAuditRecord("removeSamlIdpCertificate", model.AuditStatusFail)
 	defer c.LogAuditRec(auditRec)
 
 	if err := c.App.RemoveSamlIdpCertificate(); err != nil {