Implement min/max advertisement interval

[vinicentus]

This change allows specifying advertisement intervals.

This has been written by AI (Cursor), but verified by me. It's tested and working. See this excerpt from btmon, showing that the min & max interval are correclty set to 20ms & 50ms as specified in my application code using this library.

bluetoothd[1295]: @ MGMT Command: Add Extended Advertising Parameters (0x0054) plen 18                                                                                                  {0x0001} [hci0] 5801.230514
        Instance: 1
        Flags: 0x00015001
          Switch into Connectable mode
          Use provided duration parameter
          Use provided interval parameters
          Contain Scan Response Data
        Duration: 2
        Timeout: 0
        Min advertising interval: 20.000 msec (0x0020)
        Max advertising interval: 50.000 msec (0x0050)
        TX power: 0 dbm (0x00)
< HCI Command: LE Set Extended Advertising Parameters (0x08|0x0036) plen 25                                                                                                                  #73 [hci0] 5801.230745
        Handle: 0x01
        Properties: 0x0013
          Connectable
          Scannable
          Use legacy advertising PDUs: ADV_IND
        Min advertising interval: 20.000 msec (0x0020)
        Max advertising interval: 50.000 msec (0x0050)
        Channel map: 37, 38, 39 (0x07)
        Own address type: Public (0x00)
        Peer address type: Public (0x00)
        Peer address: 00:00:00:00:00:00 (OUI 00-00-00)
        Filter policy: Allow Scan Request from Any, Allow Connect Request from Any (0x00)
        TX power: Host has no preference (0x7f)
        Primary PHY: LE 1M (0x01)
        Secondary max skip: 0x00
        Secondary PHY: LE 1M (0x01)
        SID: 0x00
        Scan request notifications: Disabled (0x00)

I chose to base this on top of develop instead of main since the structure of Advertisment was changed in a way where the implementation was easier. Hopefully that's ok? Alternatively this could be merged into main after develop is?

[spacecheese]

Looks good to me, thanks for the PR. I have some test updates in the works I will bring in before I release a new alpha.