Windows module: Make path flattening for windres work in more cases

If either 'name' or 'name_formatted' are absolute paths,
then they are of the form:

C:\path/to/file.ext                            (example)

By only substituting slashes with the underscore, we get:

C:_path_to_file.ext

This is still not quite right, infact os.path.basename()
returns:

_path_to_file.ext

Also replace colons with underscores to overcome issues when
absolute paths are involved.

mesonbuild/modules/windows.py

@@ -145,8 +145,8 @@ class WindowsModule(ExtensionModule):
                 raise MesonException(f'Unexpected source type {src!r}. windows.compile_resources accepts only strings, files, custom targets, and lists thereof.')
 
             # Path separators are not allowed in target names
-            name = name.replace('/', '_').replace('\\', '_')
-            name_formatted = name_formatted.replace('/', '_').replace('\\', '_')
+            name = name.replace('/', '_').replace('\\', '_').replace(':', '_')
+            name_formatted = name_formatted.replace('/', '_').replace('\\', '_').replace(':', '_')
 
             res_kwargs = {
                 'output': name + '_@BASENAME@.' + suffix,