Software version

[stokito]

1. For a future we may have an option to disable sharing of OS version. Then let's not include these values to make the response smaller.
2. Fix a bug when FORM_TYPE is duplicated:

<iq type="result" to="juliet@capulet/balcony" id="12V9F-43">
<query xmlns="http://jabber.org/protocol/disco#info" node="">
<x xmlns="jabber:x:data" type="result">
<field var="FORM_TYPE" type="hidden">
<value>urn:xmpp:dataforms:softwareinfo</value>
</field>
<field var="FORM_TYPE" type="hidden">
<value>urn:xmpp:dataforms:softwareinfo</value>
</field>
<field var="software" type="text-single">
<value>Psi+</value>
</field>
<field var="software_version" type="text-single">
<value>1.5.2132 (2026-03-18, 052ffe4a)</value>
</field>
<field var="os" type="text-single">
<value>Ubuntu 25.10</value>
</field>
<field var="os_version" type="text-single">
<value></value>
</field>
</x>
</query>
</iq>

Similar PR psi-im/psi#956