refactor(esx_lscustom): code structure

[fellow25]

Description

The message that appeared when entering the custom zone now correctly disappears when the player exits the vehicle without leaving the zone.

PR Checklist

• My commit messages and PR title follow the Conventional Commits standard.
• My changes have been tested locally and function as expected.
• My PR does not introduce any breaking changes.
• I have provided a clear explanation of what my PR does, including the reasoning behind the changes and any relevant context.

[N0tNvll]

I dont see the commits with the changes in there

[fellow25]

I dont see the commits with the changes in there

[CLAassistant]

All committers have signed the CLA.