feat: block launch if Java is incompatible

Keep track of compatible Java versions from meta. Launch-step
VerifyJavaInstall will check if current instance's Java version is
compatible.
Also add override option both globally and per-instance in-case the user
doesn't care about the requirement.

launcher/ui/pages/instance/InstanceSettingsPage.ui

@@ -85,6 +85,16 @@
             </property>
            </widget>
           </item>
+          <item row="2" column="0">
+           <widget class="QCheckBox" name="skipCompatibilityCheckbox">
+            <property name="toolTip">
+             <string>If enabled, the launcher will not check if an instance is compatible with the selected Java version.</string>
+            </property>
+            <property name="text">
+             <string>Skip Java compatibility checks</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>