feat: adding a spawner for the player's avatar in the game scene [MTT-9622]

[fernando-cortez]

Description

This PR moves the spawning of a client's player NetworkObject to a scene NetworkObject. A player's NetworkObject was being spawned conveniently after the scene had been loaded, but this workflow now ensures that the player's NetworkObject is only spawned once it has been synchronized with all the scene's NetworkObjects.

Functionality should remain the same, but instead this scene NetworkBehaviour PlayerSpawner will spawn and position the player at a spawn point.

Issue Number(s)

MTT-9622

Contribution checklist

• [ N/A ] Tests have been added for the project and/or any internal package
• Release notes have been added to the project changelog file
• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• JIRA ticket ID is in the PR title or at least one commit message
• Include the ticket ID number within the body message of the PR to create a hyperlink

[hammerlerobi]

Tested and works as expected. Fixed some merge conflicts to develop. (Took changes in this PR and readded prefabs needed for TextChat in BootStrap Scene)