Added themes

All files (that used styles) were refactored to use styles directly so themes can only actually adjust colors
 - Elaborate themes would be super hard to maintain and would certainly break over time

app/src/main/res/drawable/bg_selection_circle_green.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item>
+        <shape android:shape="oval">
+            <solid android:color="#43A047" />
+        </shape>
+    </item>
+</selector>

app/src/main/res/drawable/ic_paint.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="?colorOnSurface"
+        android:pathData="M20.71,4.63L19.37,3.29C19,2.9 18.35,2.9 17.96,3.29L9,12.25L11.75,15L20.71,6.04C21.1,5.65 21.1,5 20.71,4.63M7,14A3,3 0 0,0 4,17C4,18.31 2.84,19 2,19C2.92,20.22 4.5,21 6,21A4,4 0 0,0 10,17A3,3 0 0,0 7,14Z" />
+</vector>