Add formal support for EZSP v19 (EZSP Protocol Version 19 == 0x13) in bellows

[Hedda]

Formally add support for EZSP v19 (EZSP Protocol Version 0x13) from "Zigbee SDK Version 9.1" used by Zigbee EmberZNet 9.1.0 SDK.

• https://docs.silabs.com/sisdk-release-notes/2026.6.0/sisdk-zigbee-release-notes/

Silicon Labs released "Zigbee SDK Version 9.1"" (Revision 0) as part of Simplicity SDK Version 2026.6.0 package release on 23rd of June, 2026.

• https://docs.silabs.com/sisdk-release-notes/2026.6.0/sisdk-zigbee-release-notes/sisdk-zigbee-sdk-release-notes#zigbee-sdk-version-9-1-0-release-notes-jun-23-2026

Key features overview:

• https://docs.silabs.com/sisdk-release-notes/2026.6.0/sisdk-release-notes-overview/

For reference, support for this new version was recetly also added to zigbee-herdsman too a few weeks ago:

• feat: support for EmberZNet 9.1.0 (EZSP v19 / v2026.6.0) Koenkk/zigbee-herdsman#1800

Firmware pre-release (pre-alpha) can be found via:

• Simplicity SDK 2026.6.0 NabuCasa/silabs-firmware-builder#205

and

• https://github.com/Nerivec/silabs-firmware-builder/releases/tag/v2026.6.0-pre1

Maybe no new commands that bellows use but suggest still adding these for completeness.

PS: For reference also see related discussion about bumping ZBT-2 official pre-release/alpha firmware for Simplicity SDK 2026.6.0 here:

• Simplicity SDK 2026.6.0 NabuCasa/silabs-firmware-builder#205

and

• v2026.02.23 NabuCasa/silabs-firmware-builder#190