[BUG] Label text escaping is broken

[w-lfchen]

Checklist before submitting an issue

• I have searched through the existing closed and open issues for eww and made sure this is not a duplicate
• I have specifically verified that this bug is not a common user error
• I am providing as much relevant information as I am able to in this bug report (Minimal config to reproduce the issue for example, if applicable)

Description of the bug

the label doesn't show up, the log states Failed to unescape label text

Reproducing the issue

this can happen by statically putting \\ in a label text.
this issue can be resolved by changing this to \\\\, but this is not feasible for every script.

Expected behaviour

it doesn't break

Additional context

the culprit here is the unescape crate, it is being used here.
this forces every escape in yuck to happen twice if the result should be put in a label.
i'll see whether i can file a pr to improve things.

a fix addressing this should also close #1117 (and maybe other issues)