[Enhancement] Toggle expand/collapse `To:`, `Cc:`, `Bcc:` and `Attchmnt:` fields to show multiple lines and ease edition

[Kabouik]

It would be nice if those fields could be toggled between single line (default) and multi-line, so that long lists can be easily edited. First, long lists would be more legible when expanded. Second, shell keybindings like Ctrl+a (beginning of line), Ctrl+e (end of line), Ctrl+k (delete all to the right of the cursor) and Ctrl+u (delete all to the left of the cursor) could be used to cherry pick which recipients or attachments to remove and more efficiently edit lists.

Likewise, it may make sense to enable editing with an external editor (currently Ctrl+e, but this conflicts with the above standard shell keybindings), just like currently possible for the main body of the message.

I sometimes have to send emails to >100 people and having to move left or right character by character to review my list of recipients made me think of this potential improvement. The list of attachments can also be quite long even with few attachments if their path itself contains a lot of characters.

[d99kris]

Hi @Kabouik - yes I think these are some good ideas! Will try to look into this.

[d99kris]

Improved key bindings support for email header fields has been added now, allowing use of alt-left, alt-right, alt-backspace, alt-delete (and also ctrl-a/e/u/k). This hopefully helps a little bit.

Will leave this issue open until I've checked the feasibility on expanding/collapsing the email header fields to multiple lines.

[d99kris]

Will proceed to move all feature requests into Discussions section, for a clearer separation of bugs and feature requests.