Add execute method to run callbacks and add support to asynchronous on_edit/on_click tabulator callbacks

[maximlt]

This is achieved through the addition of the run_callback method on the states that delegates to the callback call to the right context.

Should there me more usage of run_callback throughout the code base? e.g. should theon_click button events make use of it?

[codecov]

Codecov Report

Merging #3550 (3357f49) into master (0dab3ba) will increase coverage by 0.02%.
The diff coverage is 97.36%.

@@            Coverage Diff             @@
##           master    #3550      +/-   ##
==========================================
+ Coverage   82.76%   82.79%   +0.02%     
==========================================
  Files         199      199              
  Lines       27435    27470      +35     
==========================================
+ Hits        22707    22743      +36     
+ Misses       4728     4727       -1     

Impacted Files	Coverage Δ
panel/widgets/tables.py	88.77% <66.66%> (ø)
panel/io/state.py	67.92% <100.00%> (+0.68%)	⬆️
panel/tests/widgets/test_tables.py	99.63% <100.00%> (+0.01%)	⬆️
panel/io/server.py	76.56% <0.00%> (+0.20%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0dab3ba...3357f49. Read the comment docs.