Change HTextField borders, SignIn disable buttons

By default now, fields have a transparent border if not focused and
accent-color border if focused.
Set `bordered: false` for no border at all.

The register and forgot buttons on the SignIn screen are now disabled,
since their functions aren't implemented yet.

src/qml/Base/HInterfaceBox.qml

@@ -52,6 +52,7 @@ HScalingBox {
                     id: button
                     text: modelData.text
                     iconName: modelData.iconName || ""
+                    enabled: modelData.enabled === false ? false : true
                     onClicked: buttonCallbacks[modelData.name](button)
 
                     Layout.fillWidth: true

src/qml/Base/HLabeledTextField.qml

@@ -16,7 +16,6 @@ Column {
 
     HTextField {
         id: textField
-        bordered: true
         radius: 2
         width: parent.width
     }

src/qml/Base/HTextField.qml

@@ -11,7 +11,7 @@ TextField {
 
     readonly property QtObject _tf: theme.controls.textField
 
-    property bool bordered: false
+    property bool bordered: true
     property color backgroundColor: _tf.background
     property color borderColor: _tf.border
     property color focusedBackgroundColor: _tf.focusedBackground