fix: Card Browser Border and Header Height

* The header is made taller to make it accessible as a tappable element
* The vertical border between columns is removed
  * There was design consensus that this looks better

Fixes 17894
Fixes 17896

Author: argon2r

AnkiDroid/src/main/java/com/ichi2/anki/browser/BrowserMultiColumnAdapter.kt

@@ -102,10 +102,6 @@ class BrowserMultiColumnAdapter(
                     inflate(R.layout.browser_column_cell).apply {
                         columnViews.add(this as TextView)
                     }
-
-                    if (index <= value) {
-                        inflate(R.layout.browser_column_divider)
-                    }
                 }
 
                 columnViews.forEach { it.setupTextSize() }

AnkiDroid/src/main/res/drawable/browser_heading_bottom_divider.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="?attr/colorControlHighlight">
+    <item android:id="@android:id/mask">
+        <shape android:shape="rectangle">
+            <solid android:color="@android:color/white" />
+        </shape>
+    </item>
+
+    <item android:gravity="bottom">
+        <shape android:shape="rectangle">
+            <size android:height="1dp" />
+            <solid android:color="?attr/cardBrowserDivider" />
+        </shape>
+    </item>
+</ripple>

AnkiDroid/src/main/res/layout/browser_column_cell.xml

@@ -18,7 +18,7 @@
     android:layout_width="0dp"
     android:layout_height="match_parent"
     android:layout_weight="1"
-    android:paddingStart="4dp"
+    android:paddingStart="8dp"
     android:paddingVertical="1dp"
     android:layout_gravity="top"
 />

AnkiDroid/src/main/res/layout/browser_column_divider.xml

@@ -17,9 +17,10 @@
 <com.ichi2.ui.FixedTextView xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="0dp"
     android:layout_height="match_parent"
+    android:minHeight="?minTouchTargetSize"
     android:layout_weight="1"
     android:textFontWeight="700"
-    android:paddingStart="4dp"
+    android:paddingStart="8dp"
     android:textAppearance="@style/TextAppearance.AppCompat.Widget.TextView.SpinnerItem"
-    android:layout_gravity="center_vertical"
+    android:gravity="center_vertical"
 />

AnkiDroid/src/main/res/layout/browser_column_heading.xml

@@ -18,7 +18,7 @@
         <LinearLayout
             android:id="@+id/browser_column_headings"
             android:layout_width="match_parent"
-            android:background="?attr/selectableItemBackground"
+            android:background="@drawable/browser_heading_bottom_divider"
             android:orientation="horizontal"
             android:paddingVertical="2dp"
             android:layout_height="wrap_content"