Request: parameters for custom pre- and post- CWD chars

[AndydeCleyre]

Without needing to assemble a full custom prompt component array, it would be useful to specify some arbitrary content to precede and follow the current working directory component.

For example, one might prefix with a folder icon, and maybe some spaces:

AGKOZAK_PRE_DIR_CHAR='  '

or maybe put it in a "bubble":

AGKOZAK_PRE_DIR_CHAR='%F{#081937}%K{#081937}%F{green}'
AGKOZAK_POST_DIR_CHAR='%F{#081937}%k%f'

[AndydeCleyre]

I would also like to use this to italicize the directory, with \e[3m and \e[0m. Though I tried adding those directly in the source and they always came out literally on the other side, so maybe italics would need their own handling, meaning I should open a separate issue?