test(chrome): compare the hint keys and placeholder across both matchers

The page gains four fields that differ one rung at a time: a bound
label, a placeholder, a placeholder an aria-label outranks, and the name
the form gives the field. Only the placeholder rung was reachable
before, so hintText and placeholderValue named a field on the goja host
and no element at all on web for the other three, and named the field
here and nothing there for the rung the ladder passed over.

placeholder was measured empty on both hosts because nothing on the page
carried the attribute, which said nothing about it. It now names the
field the markup wrote it on and not the field whose hint is its
aria-label.

The third resolver reads the same selectors: what TranslateStringSelector
builds for a hint key has to match nothing over CDP rather than the field
carrying the value as a placeholder.

internal/driver/chrome/testdata/selector-parity.html

@@ -27,6 +27,17 @@
       <div id="login_terms" contenteditable="true">terms</div>
       <input id="login_remember" type="checkbox" aria-label="login_remember" />
     </form>
+    <!-- hintText is the accessible-name ladder rather than one attribute, so
+         these fields differ one rung at a time: a bound label, a placeholder,
+         a placeholder an aria-label outranks, and the name the form gives the
+         field. -->
+    <div id="hint_row">
+      <label id="hint_phone_label" for="hint_phone">Phone number</label>
+      <input id="hint_phone" />
+      <input id="hint_search" placeholder="Search customers" />
+      <input id="hint_amount" aria-label="Amount in rupees" placeholder="0.00" />
+      <input id="hint_code" name="verification_code" />
+    </div>
     <!-- The boolean states are derived from the live element, never written by
          the markup, so these controls differ one state at a time: a disabled
          button and an aria-disabled role control, a box ticked by script with