Added Power Saving for NRF52 companions to have extra 30% battery life

[IoTThinks]

Hi friends,
This PR is to reduce 30% power consumption for NRF52 companions.

• From 9.3mA down to 6.5mA. Measured at battery cable.
• It is enabled by default as there is no CLI in companion.
• BLE connection will be maintained in any case.

Expected behavior: You will not see any differences against MeshCore dev. Except the battery life is longer.
Your NRF52 companions can virtually have extra 30% more battery capacity.
Enjoy.

[IoTThinks]

Tested internally with RAK4631 and Xiao NRF52.
Tested by friends through two releases.

[sean-leach]

Will this also apply to repeater firmware, or just companion for now?

[sean-leach]

Just built and flashed the repeater build to my RAK 4631. Here we go!

[IoTThinks]

@sean-leach Power saving for NRF52 repeaters has been available for a while in MC 1.14.1 and PS 14.1.

CLI: powersaving on.
Reduced from 9mA down to 5.8mA.

[sean-leach]

Thank you!

[jmarcelino]

Great job! I see a 10mW reduction with this patch applied on the RAK4361

[IoTThinks]

@jmarcelino Your power visualization looks cool.

Enjoy.

[IPv777]

Hello @IoTThinks , gg for your incredible works with https://github.com/IoTThinks/EasySkyMesh/releases/
You'll save me a lot of power

[IPv777]

Please merge <3

[IoTThinks]

@IPv777 Sometimes, I feel we don't need the battery measurement at repeaters any more.
It just works with small solar panels.

Some friends with tiny / barebone RAK4631 repeaters with power saving can reduce down to 3.8mA.
It means his RAK4631 solar repeaters are very small like a palm now. He can hang them anywhere.
Enjoy.

[oltaco]

One small change and this should be good to go 👍

[IoTThinks]

Hmm, I need to rebase.
I will do that this week.

[oltaco]

Hmm, I need to rebase. I will do that this week.

No problems, it will be good to get this merged. I'm happy to resolve the merge conflicts too if you like.

[IoTThinks]

@oltaco I did a merge and rebase just now.
Minor spaces are removed. Should be OK.