layout: Add very basic support for showing text in input boxes (#32365)

This only paints text in input fields. Selection and cursor are still
not painted.

In addition to adding this feature, the change also updates the
user-agent.css with the latest from the HTML specification. Extra
padding and extraneous settings (such as a bogus line-height and
min-height) are also removed from servo.css. This leads to some new
passes.

There are some new passes, this introduces failures as inserting text
reveals issues that were hidden before. Notably:

- failures in `/html/editing/editing-0/spelling-and-grammar-checking/`:
  We do not support spell-checking.
- Most of the rest of the new failures are missing features of input
  boxes that are also missing in legacy layout.

tests/wpt/meta/html/rendering/non-replaced-elements/form-controls/text-transform.html.ini

@@ -1,2 +0,0 @@
-[text-transform.html]
-  expected: FAIL

tests/wpt/meta/html/rendering/replaced-elements/the-textarea-element/textarea-padding-bend-overlaps-content-001.tentative.html.ini

@@ -1,2 +0,0 @@
-[textarea-padding-bend-overlaps-content-001.tentative.html]
-  expected: FAIL

tests/wpt/meta/html/rendering/replaced-elements/the-textarea-element/textarea-padding-bstart-moves-content-001.tentative.html.ini

@@ -1,2 +0,0 @@
-[textarea-padding-bstart-moves-content-001.tentative.html]
-  expected: FAIL

tests/wpt/meta/html/rendering/widgets/baseline-alignment-and-overflow.tentative.html.ini

@@ -316,3 +316,21 @@
 
   [<input type="button" value="x" style="overflow: scroll; appearance: none;">]
     expected: FAIL
+
+  [<input type="range" style="overflow: visible; appearance: auto;">]
+    expected: FAIL
+
+  [<input type="range" style="overflow: visible; appearance: none;">]
+    expected: FAIL
+
+  [<input type="color" value="#000000" style="overflow: visible; appearance: auto;">]
+    expected: FAIL
+
+  [<input type="color" value="#000000" style="overflow: visible; appearance: none;">]
+    expected: FAIL
+
+  [<input type="image" src="data:(png)" alt="x" style="overflow: visible; appearance: auto;">]
+    expected: FAIL
+
+  [<input type="image" src="data:(png)" alt="x" style="overflow: visible; appearance: none;">]
+    expected: FAIL

tests/wpt/meta/html/rendering/widgets/button-layout/flex.html.ini

@@ -7,6 +7,3 @@
 
   [align-items:stretch should work]
     expected: FAIL
-
-  [align-items:flex-start should work]
-    expected: FAIL

tests/wpt/meta/html/rendering/widgets/button-layout/input-type-button-newline-2.html.ini

@@ -1,2 +0,0 @@
-[input-type-button-newline-2.html]
-  expected: FAIL

tests/wpt/meta/html/rendering/widgets/button-layout/input-type-button-newline.html.ini

@@ -1,2 +0,0 @@
-[input-type-button-newline.html]
-  expected: FAIL

tests/wpt/meta/html/rendering/widgets/field-sizing-input-number.html.ini

@@ -8,9 +8,6 @@
   [number: Explicit height and auto width]
     expected: FAIL
 
-  [number: Text caret is taller than the placeholder]
-    expected: FAIL
-
   [number: Text caret is shorter than the placeholder]
     expected: FAIL
 

tests/wpt/meta/html/rendering/widgets/input-checkbox-switch-rtl.tentative.html.ini

@@ -0,0 +1,2 @@
+[input-checkbox-switch-rtl.tentative.html]
+  expected: FAIL