nls: add Arabic hamza compose sequences

These sequences are intended for use in the ara(mac-phonetic) and my(phonetic) layouts. They are based on the following layouts listed in the CLDR:

• https://github.com/unicode-org/cldr/blob/release-43/keyboards/osx/ar-t-k0-osx-qwerty.xml
• https://github.com/unicode-org/cldr/blob/release-43/keyboards/osx/ms-t-k0-osx.xml

The sequences are listed in the <transforms> section, and are reproduced below:

<transforms type="simple">
	<transform from="ء\u{64E}" to="آ"/> <!--  ءَ → آ -->
	<transform from="ء\u{650}" to="إ"/> <!--  ءِ → إ -->
	<transform from="ء " to="ء"/>
	<transform from="ء\u{A0}" to="ء"/>
	<transform from="ء!" to="إ"/>
	<transform from="ء١" to="إ"/>
	<transform from="ءا" to="أ"/>
	<transform from="ءس" to="ئ"/>
	<transform from="ءو" to="ؤ"/>
	<transform from="ءي" to="ئ"/>
	<transform from="ءى" to="ئ"/>
</transforms>

We limit ourselves to the sequences that strictly combine a character and a hamza, and generate that character with a hamza on it, following the behavior in sequences of other dead keys. Additional sequences, potentially for other layouts as well, could be added later on as necessary.