Add the ability to create IMAP folders

[gavinwa]

Thunderbird Android has no method to create a new IMAP folder. Please add the ability to create folders.

[Wacko37]

Wow, finally we have Thunderbird for Android, so sick of all the other offerings.

Would love to see the "create folder" option.

Thanks.

[yan12125]

Looks like this is under consideration https://github.com/thunderbird/thunderbird-android/issues/1389