Modals: Submit/accept by pressing enter

[Taitava]

Idea by @imeed166 in https://github.com/Taitava/obsidian-shellcommands/discussions/201#discussioncomment-2654854

Modals that should have this possibility:

• [x] Prompts
• [x] Deletion modal (for shell commands, prompts, prompt fields, custom variables)
• [x] Confirmation modal (when a shell command asks a confirmation before execution)

Other:

• [x] Create a hidden setting enable_enter_key_to_approve_modals (on by default) that can be used to disable this feature in case a user wants to prevent accidental enter key presses.
• [x] Add to CHANGELOG.md.
• [x] Add the enable_enter_key_to_approve_modals setting to documentation.
• [x] Add mentions of the enter key press to History sections of modals that have a documentation page, at least Prompts and Ask after execution (that also has now the enter keypress possibility, although it's probably not used much, as most of the time the focus in that modal is in a textarea, which prevents closing the modal by ptessing the enter key).

[Taitava]

Done. Will be released in 0.13.0.

[Taitava]

Released.