Fix(tmux): better tmux session handling for multiple instance on same server / user session

[cclecle]

Description

Force tmux to create a new trmux server instance for each game instance to avoid sharing same pid. This allow systemd to differentiate games server instance correctly.

Update consist to change: tmux <some options> with: tmux -L "${sessionname}" <some options>

Fixes #3763

Type of change

• [X] Bug fix (a change which fixes an issue).
• [ ] New feature (change which adds functionality).
• [ ] New Server (new server added).
• [ ] Refactor (restructures existing code).
• [ ] Comment update (typo, spelling, explanation, examples, etc).

Checklist

PR will not be merged until all steps are complete.

• [X] This pull request links to an issue.
• [X] This pull request uses the develop branch as its base.
• [X] This pull request Subject follows the Conventional Commits standard.
• [X] This code follows the style guidelines of this project.
• [X] I have performed a self-review of my code.
• [X] I have checked that this code is commented where required.
• [X] I have provided a detailed with enough description of this PR.
• [X] I have checked If documentation needs updating.

Documentation

No update needed.

[h3o66]

Not sure about this one. @dgibbs64 please have a look

[dgibbs64]

Caution needs to happen with tmux changes. Problems have occurred before. I will need to review and test :)