tweak(mono-rt2): change script initialization method

[DaniGP17]

Goal of this PR

Change the way scripts are initialized to prevent a BaseClass with the EnableOnLoad(false) attribute from loading ticks, events and nui callbacks.

How is this PR achieving the goal

First of all I have modified the Initialize function, now when I initialize the script it will call the Enable function again to load the ticks, events and nui callbacks.
Finally, I have eliminated the functions that recorded ticks, callbacks and events when they were added.

This PR applies to the following area(s)

ScRT: C#

Successfully tested on

Game builds: .

Platforms: Windows

Checklist

• Code compiles and has been tested successfully.
• Code explains itself well and/or is documented.
• My commit message explains what the changes do and what they are for.
• No extra compilation warnings are added by these changes.

Fixes issues

fixes #2476