decompiler: Implement support for bindings

The .ui files for tests were taken from GTK test suite.

blueprintcompiler/decompiler.py

@@ -357,6 +357,45 @@ def decompile_property(
     return gir
 
 
+@decompiler("binding")
+def decompile_binding(ctx: DecompileCtx, gir, name):
+    name = name.replace("_", "-")
+    ctx.print(f"{name}: bind ", newline=False)
+    ctx.end_block_with(";")
+    return gir
+
+
+@decompiler("lookup", cdata=True)
+def decompile_lookup(ctx: DecompileCtx, gir, name, cdata, type=None):
+    name = name.replace("_", "-")
+
+    if cdata is not None:
+        ctx.print(cdata, newline=False)
+
+    cast = f" as <{type}>" if type is not None else ""
+    ctx.end_block_with(f"{cast}.{name}", newline_after=False, indent=False)
+
+    return gir
+
+
+@decompiler("constant", cdata=True)
+def decompile_constant(ctx: DecompileCtx, gir, cdata, type=None):
+    cast = f" as <{type}>" if type is not None else ""
+    ctx.print(f"{cdata}{cast}", newline=False, indent=False)
+
+    return gir
+
+
+@decompiler("closure")
+def decompile_closure(ctx: DecompileCtx, gir, function, type):
+    ctx.print(f"{function}(", newline=False)
+    ctx.separate_block_elements_with(f", ")
+    cast = f" as <{type}>"
+    ctx.end_block_with(f"){cast}", newline_after=False, indent=False)
+
+    return gir
+
+
 @decompiler("attribute", cdata=True)
 def decompile_attribute(
     ctx, gir, name, cdata, translatable="false", comments=None, context=None