Made config global using singleton-like approach.
Pylint related fixes.
Prevent sending sigint to processes started by virtui when ctrl-c is hit.
No need some awkward substitutions, just substitute where possible. (and if impossible - crash = need to fix)
Warn about failed substitution during building command list instead of crashing.
Set terminal title once virtui is started (maybe add new titles in future, such as virtui (DOMAIN_XYZ)
Sort domain selection by name.