allow terminating char to clear search term

[naosense]

Hi @imsnif, I found something interesting after I walked around the code base.
Because \0 is not allowed here,

zellij/zellij-server/src/tab/mod.rs

Lines 2610 to 2611 in 5793af7

	// It only allows printable unicode, delete and backspace keys.
	let is_updatable = buf.iter().all(|u| matches!(u, 0x20..=0x7E | 0x08 | 0x7F));

it wouldn't step in this branch below.

zellij/zellij-server/src/panes/terminal_pane.rs

Lines 653 to 656 in 5793af7

	match needle {
	TERMINATING_STRING => {
	self.search_term = String::new();
	},

I don't know if this is on purpose or just an oversight, if this is on purpose, I will close this pr, thanks.

Related to #1817

[imsnif]

Good find @naosense !! This seems to make sense to me (and is working for me). @msirringhaus - what do you think? Do you see any downsides to implementing this?

[msirringhaus]

LGTM!