Add fixture `stairville/dds-405-dmx-dimmer-switcher`

[FloEdelmann]

• Add fixture stairville/dds-405-dmx-dimmer-switcher

Thank you @pitchbent!

[github-actions[bot]]

Export files validity

(Output of test script tests/github/exports-valid.js.)

Test the exported files of selected fixtures against the plugins' export tests. You can run a plugin's export tests by executing: $ node cli/run-export-test.js -p <plugin name> <fixtures>

✔️ stairville / dds-405-dmx-dimmer-switcher: d-light / attributes-correctness

• ✔️ stairville/dds-405-dmx-dimmer-switcher-1-Channel Dimm All.xml
• ✔️ stairville/dds-405-dmx-dimmer-switcher-4-Channel Dimm Single.xml

✔️ stairville / dds-405-dmx-dimmer-switcher: dmxcontrol3 / channel-numbers

• ✔️ stairville-dds-405-dmx-dimmer-switcher-1-Channel-Dimm-All.xml
• ✔️ stairville-dds-405-dmx-dimmer-switcher-4-Channel-Dimm-Single.xml

✔️ stairville / dds-405-dmx-dimmer-switcher: dragonframe / json-schema-conformity

• ✔️ stairville/dds-405-dmx-dimmer-switcher.json
• ✔️ manufacturers.json

✔️ stairville / dds-405-dmx-dimmer-switcher: millumin / json-schema-conformity

• ✔️ stairville/dds-405-dmx-dimmer-switcher.json

✔️ stairville / dds-405-dmx-dimmer-switcher: qlcplus_4.12.2 / fixture-tool-validation

• ✔️ fixtures/Stairville-DDS-405-DMX-Dimmer-&-Switcher.qxf

✔️ stairville / dds-405-dmx-dimmer-switcher: qlcplus_4.12.2 / xsd-schema-conformity

• ✔️ fixtures/Stairville-DDS-405-DMX-Dimmer-&-Switcher.qxf

[kengruven]

Very similar to the "DDS 504 LC" (#3502), and with the same DMX mapping. Do we want to combine them?