Remove replace directives and use own fork to make go get work again (#1028)

See https://github.com/golang/go/issues/30354
go get doesn't honor the go.mod replace options.

vendor/github.com/matterbridge/msgraph.go/beta/SiteCollectionModel.go

@@ -0,0 +1,15 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// SiteCollection undocumented
+type SiteCollection struct {
+	// Object is the base model of SiteCollection
+	Object
+	// DataLocationCode undocumented
+	DataLocationCode *string `json:"dataLocationCode,omitempty"`
+	// Hostname undocumented
+	Hostname *string `json:"hostname,omitempty"`
+	// Root undocumented
+	Root *Root `json:"root,omitempty"`
+}