Implement Additional Variables

[Jacki3]

The Engine is missing some key variables which would be useful for conditions, saving etc. which include:

• Booleans
• Floats
• Strings

There may be other variables that will be added but this will be tracked accordingly.

[Jacki3]

Have implemented the above variables with string variable only using single line currently so this must be implemented; strings also substitute certain special characters using derived classes from Fungus code base to avoid errors with funky strings.

Leaving this open for now but will merge the branch into main and add multi lines later down the line.