UI bug in settings: Wrong shell names displayed under shell command previews

[Taitava]

Discussed in https://github.com/Taitava/obsidian-shellcommands/discussions/364

^{Originally posted by **seatrout** August 3, 2023} When a custom shell is set up for a command (in this instance WSL on a windows machine) the main UI screen still shows the default shell — see screenshot. 

Main fixes:

• [x] Fix: Shell command preview shows an incorrect shell name when the command's shell differs from the operating system's default shell.
• [x] Fix: When shell is changed, the shell's name should change immediately in the shell command settings modal, and also in the main settings modal. Without this fix, changes could only be seen after modal content is refreshed.

Additonal fixes:

• [x] Fix: Changing the shell should also change escape characters in shell command preview texts, both in shell command settings modal, and in main settings modal.
• [x] Fix: When inputting operating system specific versions of shell commands, the shell name under Default shell command field should be updated, too.

[Taitava]

Fixed. Will be released in 0.20.1.

[Taitava]

Released.