bin: Rewrite Clapper player binary

A rewritten Clapper video player made using "Clapper" and "ClapperGtk" libraries.

Since both libraries from this repo are in C, newly rewritten Clapper binary is also in C to
avoid mixing different programming languages in a single repo, thus making maintenance easier.
Not depending on GJS gives us also an additional benefit of supporting different operating
systems or linux shells without pulling GJS as dependency.

Licensed under GPL-3.0-or-later.

src/bin/clapper-app/ui/clapper-app-uri-dialog.ui

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface domain="clapper-app">
+  <object class="AdwMessageDialog" id="dialog">
+    <property name="modal">true</property>
+    <property name="width-request">420</property>
+    <property name="heading" translatable="yes">Add URI</property>
+    <property name="body" translatable="yes">Insert an URI to be added to playback queue</property>
+    <property name="close-response">cancel</property>
+    <property name="default-response">add</property>
+    <property name="extra-child">
+      <object class="GtkEntry">
+        <property name="halign">fill</property>
+        <property name="valign">center</property>
+        <property name="hexpand">true</property>
+        <property name="activates-default">true</property>
+        <property name="truncate-multiline">true</property>
+        <property name="input-purpose">url</property>
+        <property name="placeholder-text" translatable="yes">Enter or drop URI here</property>
+      </object>
+    </property>
+    <responses>
+      <response id="cancel" translatable="yes">Cancel</response>
+      <response id="add" translatable="yes" appearance="suggested" enabled="false">Add</response>
+    </responses>
+  </object>
+</interface>