Touch up settings: alignment, spacing, error states

Fixes https://github.com/vector-im/riot-web/issues/10554

Issues fixed:
* Fields were not ~30px from the avatar (too much right margin)
* Tooltips overflowed the dialog on some resolutions
* SetIdServer didn't have an error state for making the field red
* Spacing between sections in Discovery was wrong (fixed by just removing the problematic n+2 selector - it didn't help anything)

res/css/_common.scss

@@ -561,5 +561,10 @@ input[type=text]:focus, input[type=password]:focus, textarea:focus {
 }
 
 @define-mixin mx_Settings_fullWidthField {
-    margin-right: 200px;
+    margin-right: 100px;
 }
+
+@define-mixin mx_Settings_tooltip {
+    // So it fits in the space provided by the page
+    max-width: 120px;
+}

res/css/views/settings/_ProfileSettings.scss

@@ -26,10 +26,6 @@ limitations under the License.
     height: 4em;
 }
 
-.mx_ProfileSettings_controls .mx_Field {
-    margin-right: 100px;
-}
-
 .mx_ProfileSettings_controls .mx_Field:first-child {
     margin-top: 0;
 }

res/css/views/settings/_SetIdServer.scss

@@ -17,3 +17,7 @@ limitations under the License.
 .mx_SetIdServer .mx_Field_input {
     @mixin mx_Settings_fullWidthField;
 }
+
+.mx_SetIdServer_tooltip {
+    @mixin mx_Settings_tooltip;
+}

res/css/views/settings/_SetIntegrationManager.scss

@@ -31,3 +31,7 @@ limitations under the License.
     display: inline-block;
     padding-left: 5px;
 }
+
+.mx_SetIntegrationManager_tooltip {
+    @mixin mx_Settings_tooltip;
+}

res/css/views/settings/tabs/_SettingsTab.scss

@@ -70,17 +70,6 @@ limitations under the License.
     word-break: break-all;
 }
 
-.mx_SettingsTab .mx_SettingsTab_subheading:nth-child(n + 2) {
-    // TODO: This `nth-child(n + 2)` isn't working very well since many sections
-    // add intermediate elements (mostly because our version of React requires
-    // them) which throws off the numbering and results in many subheading
-    // missing margins.
-    // See also https://github.com/vector-im/riot-web/issues/10554
-    // These views have a lot of the same repetitive information on it, so
-    // give them more visual distinction between the sections.
-    margin-top: 25px;
-}
-
 .mx_SettingsTab a {
     color: $accent-color-alt;
 }

src/components/views/elements/Field.js

@@ -51,6 +51,9 @@ export default class Field extends React.PureComponent {
         // If specified, contents will appear as a tooltip on the element and
         // validation feedback tooltips will be suppressed.
         tooltipContent: PropTypes.node,
+        // If specified alongside tooltipContent, the class name to apply to the
+        // tooltip itself.
+        tooltipClassName: PropTypes.string,
         // All other props pass through to the <input>.
     };
 
@@ -177,8 +180,9 @@ export default class Field extends React.PureComponent {
         const Tooltip = sdk.getComponent("elements.Tooltip");
         let fieldTooltip;
         if (tooltipContent || this.state.feedback) {
+            const addlClassName = this.props.tooltipClassName ? this.props.tooltipClassName : '';
             fieldTooltip = <Tooltip
-                tooltipClassName="mx_Field_tooltip"
+                tooltipClassName={`mx_Field_tooltip ${addlClassName}`}
                 visible={this.state.feedbackVisible}
                 label={tooltipContent || this.state.feedback}
             />;

src/components/views/settings/SetIdServer.js

@@ -319,7 +319,7 @@ export default class SetIdServer extends React.Component {
                     "won't be discoverable by other users and you won't be " +
                     "able to invite others by email or phone.",
                 )}</span>
-                <AccessibleButton onClick={this._onDisconnectClicked} kind="danger">
+                <AccessibleButton onClick={this._onDisconnectClicked} kind="danger_sm">
                     {discoButtonContent}
                 </AccessibleButton>
             </div>;
@@ -341,6 +341,9 @@ export default class SetIdServer extends React.Component {
                     value={this.state.idServer}
                     onChange={this._onIdentityServerChanged}
                     tooltipContent={this._getTooltip()}
+                    tooltipClassName="mx_SetIdServer_tooltip"
+                    disabled={this.state.busy}
+                    flagInvalid={!!this.state.error}
                 />
                 <AccessibleButton type="submit" kind="primary_sm"
                     onClick={this._checkIdServer}

src/components/views/settings/SetIntegrationManager.js

@@ -196,6 +196,7 @@ export default class SetIntegrationManager extends React.Component {
                     autoComplete="off"
                     onChange={this._onUrlChanged}
                     tooltipContent={this._getTooltip()}
+                    tooltipClassName="mx_SetIntegrationManager_tooltip"
                     disabled={this.state.busy}
                     flagInvalid={!!this.state.error}
                 />