extmod/modbluetooth: Add abort function.

[AJMansfield]

Summary

Adds a function for aborting an in-progress bluetooth operation.

Testing

In progress.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.38%. Comparing base (78ff170) to head (16f9190).
⚠️ Report is 3 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #18567   +/-   ##
=======================================
  Coverage   98.38%   98.38%           
=======================================
  Files         171      171           
  Lines       22300    22300           
=======================================
  Hits        21939    21939           
  Misses        361      361           

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[github-actions]

Code size report:

Reference:  all: Bump version to 1.27.0. [78ff170]
Comparison: extmod/modbluetooth: Add abort function. [merge of 16f9190]
  mpy-cross:    +0 +0.000% 
   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
     mimxrt:    +0 +0.000% TEENSY40
        rp2:   +64 +0.007% RPI_PICO_W
       samd:    +0 +0.000% ADAFRUIT_ITSYBITSY_M4_EXPRESS
  qemu rv32:    +0 +0.000% VIRT_RV32