Adding metric_self_sufficiency

What's Changed

Added new metric_self_sufficiency

When in expert mode you can skew towards avoiding the use of the grid and towards using only your own generated energy.

• Adding metric_self_sufficiency by @springfall2008 in #1217
• Fixes for metric self sufficiency by @springfall2008 in #1226

Disabled metric_battery_cycle by default

Too many hassle with this feature (why is this plan not the cheapest), so turned it off by default. Can be enabled in expert mode only.

• Disable metric battery cycle by default by @springfall2008 in #1225

Bug fixes/documentation updates

• Avoid divide by 0 when load is zero by @springfall2008 in #1227
• Update givenergy_cloud.yaml by @springfall2008 in #1212
• Update video-guides.md by @springfall2008 in #1215

Full Changelog: v8.0.0...v8.1.0