calendar-management/edit: Use external-link-symbolic icon

As per mockups.

src/gui/calendar-management/gcal-edit-calendar-page.ui

@@ -49,7 +49,7 @@
 
                         <child>
                           <object class="GtkImage">
-                            <property name="icon-name">settings-symbolic</property>
+                            <property name="icon-name">external-link-symbolic</property>
                             <property name="accessible-role">presentation</property>
                           </object>
                         </child>

src/gui/icons/external-link-symbolic.svg

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" height="16px" viewBox="0 0 16 16" width="16px"><path d="m 3 2 c -1.660156 0 -3 1.339844 -3 3 v 8 c 0 1.660156 1.339844 3 3 3 h 8 c 1.660156 0 3 -1.339844 3 -3 v -4 c 0 -0.550781 -0.449219 -1 -1 -1 s -1 0.449219 -1 1 v 4 c 0 0.554688 -0.445312 1 -1 1 h -8 c -0.554688 0 -1 -0.445312 -1 -1 v -8 c 0 -0.554688 0.445312 -1 1 -1 h 4 c 0.550781 0 1 -0.449219 1 -1 s -0.449219 -1 -1 -1 z m 7 -2 c -0.550781 0 -1 0.449219 -1 1 s 0.449219 1 1 1 h 2.585938 l -5.292969 5.289062 c -0.390625 0.394532 -0.390625 1.027344 0 1.417969 s 1.023437 0.390625 1.414062 0 l 5.292969 -5.292969 v 2.585938 c 0 0.550781 0.449219 1 1 1 s 1 -0.449219 1 -1 v -5 c 0 -0.085938 -0.011719 -0.171875 -0.035156 -0.257812 c -0.023438 -0.085938 -0.054688 -0.167969 -0.101563 -0.242188 c -0.042969 -0.074219 -0.09375 -0.144531 -0.15625 -0.207031 c -0.015625 -0.011719 -0.03125 -0.023438 -0.046875 -0.035157 c -0.054687 -0.050781 -0.117187 -0.09375 -0.183594 -0.128906 c -0.035156 -0.019531 -0.074218 -0.035156 -0.113281 -0.0468748 c -0.050781 -0.0234374 -0.101562 -0.0390624 -0.15625 -0.0507812 c -0.039062 -0.0117188 -0.082031 -0.015625 -0.121093 -0.0195312 c -0.03125 -0.00781255 -0.058594 -0.00781255 -0.085938 -0.0117188 z m 0 0" fill="#222222"/></svg>

src/gui/icons/icons.gresource.xml

@@ -5,6 +5,6 @@
     <file compressed="true">calendar-month-symbolic.svg</file>
     <file compressed="true">calendar-week-symbolic.svg</file>
     <file compressed="true">calendar-today-symbolic.svg</file>
-    <file compressed="true">settings-symbolic.svg</file>
+    <file compressed="true">external-link-symbolic.svg</file>
   </gresource>
 </gresources>

src/gui/icons/settings-symbolic.svg

@@ -1,2 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<svg xmlns="http://www.w3.org/2000/svg" height="16px" viewBox="0 0 16 16" width="16px"><path d="m 7.5 1.019531 c -0.550781 0 -0.996094 0.445313 -0.996094 0.996094 v 0.453125 c -0.472656 0.128906 -0.929687 0.320312 -1.355468 0.566406 l -0.324219 -0.324218 c -0.390625 -0.390626 -1.019531 -0.390626 -1.410157 0 l -0.703124 0.707031 c -0.390626 0.390625 -0.390626 1.019531 0 1.410156 l 0.320312 0.320313 c -0.246094 0.425781 -0.433594 0.882812 -0.5625 1.355468 h -0.453125 c -0.550781 0 -0.996094 0.445313 -0.996094 0.996094 v 1 c 0 0.550781 0.445313 0.996094 0.996094 0.996094 h 0.449219 c 0.132812 0.472656 0.320312 0.929687 0.566406 1.355468 l -0.320312 0.320313 c -0.390626 0.390625 -0.390626 1.019531 0 1.410156 l 0.703124 0.707031 c 0.390626 0.390626 1.019532 0.390626 1.410157 0 l 0.320312 -0.320312 c 0.429688 0.242188 0.882813 0.433594 1.359375 0.558594 v 0.457031 c 0 0.550781 0.445313 0.996094 0.996094 0.996094 h 0.996094 c 0.554687 0 1 -0.445313 1 -0.996094 v -0.453125 c 0.472656 -0.128906 0.929687 -0.320312 1.355468 -0.566406 l 0.320313 0.324218 c 0.390625 0.390626 1.019531 0.390626 1.410156 0 l 0.707031 -0.707031 c 0.390626 -0.390625 0.390626 -1.019531 0 -1.410156 l -0.320312 -0.320313 c 0.242188 -0.425781 0.433594 -0.882812 0.558594 -1.355468 h 0.453125 c 0.554687 0 1 -0.445313 1 -0.996094 v -1 c 0 -0.550781 -0.445313 -0.996094 -1 -0.996094 h -0.449219 c -0.128906 -0.472656 -0.320312 -0.929687 -0.566406 -1.355468 l 0.324218 -0.320313 c 0.390626 -0.390625 0.390626 -1.019531 0 -1.410156 l -0.707031 -0.707031 c -0.390625 -0.390626 -1.019531 -0.390626 -1.410156 0 l -0.320313 0.320312 c -0.425781 -0.242188 -0.882812 -0.429688 -1.355468 -0.558594 v -0.457031 c 0 -0.550781 -0.445313 -0.996094 -1 -0.996094 z m 0.515625 3.976563 c 1.660156 0 3 1.34375 3 3 s -1.339844 3 -3 3 c -1.65625 0 -3 -1.34375 -3 -3 s 1.34375 -3 3 -3 z m 0 0"/></svg>