Extract Password field from Registration into a reusable component

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

res/css/views/auth/_AuthBody.scss

@@ -146,9 +146,3 @@ limitations under the License.
 .mx_AuthBody_spinner {
     margin: 1em 0;
 }
-
-.mx_AuthBody_passwordScore {
-    height: 4px;
-    position: absolute;
-    top: -12px;
-}

res/css/views/auth/_PassphraseField.scss

@@ -0,0 +1,57 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+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.
+*/
+
+$PassphraseStrengthHigh: $accent-color;
+$PassphraseStrengthMedium: $username-variant5-color;
+$PassphraseStrengthLow: $notice-primary-color;
+
+.mx_PassphraseField {}
+
+@define-mixin ProgressBarColour $colour {
+    color: $colour;
+    &::-moz-progress-bar {
+        background-color: $colour;
+    }
+    &::-webkit-progress-value {
+        background-color: $colour;
+    }
+}
+
+progress.mx_PassphraseField_progress {
+    appearance: none;
+    width: 100%;
+    border: 0;
+    height: 4px;
+    position: absolute;
+    top: -12px;
+
+    border-radius: 2px;
+    &::-moz-progress-bar {
+        border-radius: 2px;
+    }
+    &::-webkit-progress-bar,
+    &::-webkit-progress-value {
+        border-radius: 2px;
+    }
+
+    @mixin ProgressBarColour $PassphraseStrengthLow;
+    &[value="2"], &[value="3"] {
+        @mixin ProgressBarColour $PassphraseStrengthMedium;
+    }
+    &[value="4"] {
+        @mixin ProgressBarColour $PassphraseStrengthHigh;
+    }
+}