Minor quality of life changes (capital Energenie, missing semi-colon, package version outputs)

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Hello! Again, thanks for the great work on this. I'd like to be able to help make it more awesome, if you'd be interested in that!

This first pull request contains some very minor suggestions that have helped me so far when setting up my development environment:

• The Energenie name in the HA discovery packets was lower case, which made it feel lesser alongside the other devices in my HA instance that have capitalised brand names 😅
• There was a missing semi-colon; tiny
• This one might be more controversial: Could I suggest we bring through the package version into the app runtime, so that it can be a) used at logging start but also b) in the discovery packages; the firmware property that the sw discovery property ends up in, is perfectly suited for displaying version numbers

Hope you like this and are interested in further collaboration. I've submitted #41 too that might be even further controversial, so I'll split it into its own for a separate discussion

(apologies for closing the first version of this PR, I accidentally submitted from my develop branch rather than a feature-specific branch and I am new to this so wasn't sure how to repoint it without recreating the PR)

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According to this hard to find bit on this page about discovery messages, sw already represents sw_version... I'm not sure why this isn't on the page you linked!