update nushell init script

[Bahex]

1. Made __zoxide_z more idiomatic
2. Updated the hook initialization to avoid breakage on nushell's future 0.102.0 release

To expand on hook initialization:
After nushell/nushell#14704 (comment), starting sub shells would make zoxide's init script throw an error.

With this PR $env.__zoxide_hooked is no longer used. Instead, the list of hooks are checked directly to see if zoxide's hook has already been added.

I checked the new init script on both nushell version 0.89.0 and the latest nushell nightly.
Minimum supported version of nushell doesn't need to change and can be kept at 0.89.0

[binChris]

I currently have an issue with the generated nushell script. It seems instead of

if (not ($env | default false __zoxide_hooked | get __zoxide_hooked)) {

it must be

if (not ($env | default false __zoxide_hooked | get __zoxide_hooked | into bool)) {

Note the added | into bool. Without it, the script errors out on this line because for some reason the value is read as string.

Should I make a PR for this or is this PR going to merged?

[KamilKleina]

Is it ionly my problem that zoxide stopped adding paths to it's db?

[Alan-TheGentleman]

@KamilKleina not at all, the only way it works is using zoxide add /path but is tedious

[Alan-TheGentleman]

@KamilKleina FIXED !!

this is my commit for my personal configs which solve the issue for now until a proper fix !!
Gentleman-Programming/Gentleman.Dots@c00622d

zoxide adds new paths and everything. Enjoy !

[ajeetdsouza]

Thanks! Loving the new Nushell syntax :)