Fix NewPairings flag and add GetNewPairings paging.

[kareltucek]

Contains fixes for #980

Waiting for @ert78gb to test and implement Agent side.

Migrated from UltimateHackingKeyboard/firmware80#369

[ert78gb]

I am implementing the feature. I paired my UHK80 to my notebook via bluetooth . Everything worked as described in the #980 (comment). Why I implemented the feature I saved the user config because I modified the brightness of the backlighting. Also paired and un-paired the dongle because I tested something in the process.
I don't remember the exact order of what I did.
But currently, the device status does not report any new BLE paired device available. I also checked the 0 12 0 USB command and it returns with 0-s.
I unpaired and paired again my keyboard and computer but the still not see any new BLE paired devices.
I also power cycled the keyboard and uploaded the firmware again and no changes.

How could I "reset" the keyboard state to report new BLE address(es) again?

[kareltucek]

@ert78gb I have a fixed a bug that made bond-clearing on reboot not work. Sorry for also rebasing this branch while doing so.

A few notes:

• unknown bonds (those not present in host connnections) are (should be) cleared on every config application. I.e., on reboot and on saving from Agent.
• in this branch, restarting HID advertisement may be failing. In that case, please reset (or powercycle or kernel reboot cold) your UHK.

[ert78gb]

Sorry for also rebasing this branch while doing so.

I wanted to ask. I support to keep branches up to date. I am fine with merge and rebase too.

[kareltucek]

(I am fan of keeping stuff up to date, but I normally favor merges over rebases unless there is a good reason to rebase.)

[mondalaci]

@ert78gb I rely on you regarding when to merge this. Please let me know when you figure it out.

[ert78gb]

I am working on it tomorrow.

[kareltucek]

This diverge has gotten too far out of hand -> merging. (Reason: regressions and conflicts regarding hardware config load order.)