Make some legacy cells conform Reusable & Themable, add some new

Riot/Modules/Common/Views/InsettedTextField.swift

@@ -0,0 +1,39 @@
+// 
+// Copyright 2020 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import UIKit
+
+class InsettedTextField: UITextField {
+    
+    var insets: UIEdgeInsets = .zero {
+        didSet {
+            setNeedsLayout()
+        }
+    }
+    
+    override func placeholderRect(forBounds bounds: CGRect) -> CGRect {
+        return bounds.inset(by: insets)
+    }
+    
+    override func textRect(forBounds bounds: CGRect) -> CGRect {
+        return bounds.inset(by: insets)
+    }
+    
+    override func editingRect(forBounds bounds: CGRect) -> CGRect {
+        return bounds.inset(by: insets)
+    }
+    
+}