Resolves an exploit introduced by overextended#515 (see #55) that allows bad actors to replicate an excessive number of props and force players within sync range to crash. This is based on changes by @Maximus7474 but with some additional fixes/improvements.

• Limits the number of props that can be spawned using convar ox:progressPropLimit.
• Adds validation for requested models, ensuring playerProps are only stored when a valid entity is created.
• Invalid models will no longer error and stop execution of the statebag handler.
• Adds support for strict state bags.
• Disallows spawning additional props for players who already have attached props.

If you aren't already, you should be aiming to support setr sv_stateBagStrictMode 1 in all your scripts to prevent unverified client-set values from being synced to all players.