feat: settings: add a check to instantly send email

[ssiyad]

This PR adds a check in Frappe Desk Settings to decide if the reply e-mail should be sent instantly (instead of adding to a queue)

[codecov]

Codecov Report

Patch coverage: 12.50% and no project coverage change.

Comparison is base (7d7c6b8) 12.47% compared to head (be30327) 12.47%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1061   +/-   ##
=======================================
  Coverage   12.47%   12.47%           
=======================================
  Files          52       52           
  Lines        1739     1747    +8     
=======================================
+ Hits          217      218    +1     
- Misses       1522     1529    +7     

Impacted Files	Coverage Δ
frappedesk/frappedesk/doctype/ticket/ticket.py	21.71% <12.50%> (-0.18%)	⬇️

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