Add initial Microsoft Teams support

Documentation on https://github.com/42wim/matterbridge/wiki/MS-Teams-setup

vendor/github.com/yaegashi/msgraph.go/beta/UserIdentityModel.go

@@ -0,0 +1,17 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// UserIdentity undocumented
+type UserIdentity struct {
+	// Object is the base model of UserIdentity
+	Object
+	// ID undocumented
+	ID *string `json:"id,omitempty"`
+	// DisplayName undocumented
+	DisplayName *string `json:"displayName,omitempty"`
+	// IPAddress undocumented
+	IPAddress *string `json:"ipAddress,omitempty"`
+	// UserPrincipalName undocumented
+	UserPrincipalName *string `json:"userPrincipalName,omitempty"`
+}