Add support for expressions in the inline chat commands

[Azurelol]

Adds support for evaluating expressions provided in the Expressions module, property referencing and function invocation in the inline chat commands such as @DMG, @HEAL, @GAIN, @LOSS

It adds support for the following:

• @item|actor.<property>
• $<variable> : These would be shorthands for very common usages like item level, which would be $il, can also support alias $sl
• &<macro>: for custom functions that the system can provide. The most beneficial one to provide would be the one that picks a value based on the character's level. I went with &step(40,50,60) .
• minor|heavy|massive effect: Using the level of the actor to calculate the amount

[KSops]

Implementing this specifically for inline effects is fine for now, but I think eventually being able to handle dynamic expressions in other places will be beneficial and having a standardized DSL for the entire project would help.
So a utility module/class for dynamic evaluation that takes a string to parse and evaluate against a given context. And that way consumers can simply call an exposed interface call like evaluate(value: string, context: object)
That way we can refence this common module for how the DSL works instead of worrying about specific contexts in which evaluation happens.

[Azurelol]

Implementing this specifically for inline effects is fine for now, but I think eventually being able to handle dynamic expressions in other places will be beneficial and having a standardized DSL for the entire project would help.
So a utility module/class for dynamic evaluation that takes a string to parse and evaluate against a given context. And that way consumers can simply call an exposed interface call like evaluate(value: string, context: object)
That way we can refence this common module for how the DSL works instead of worrying about specific contexts in which evaluation happens.

Oh yeah, I definitely agree with providing a standard API for handling expression evaluation for the DSL in the system. I will go ahead and factor that out into its own class.

[Azurelol]

It's been factored out and a bit simpler to reason about now that it's on its own module.

[Azurelol]

One last question for the time being is to decide whether to use a different symbol for executing functions (atm $) or use the same one as property referencing @. If we use different ones then we can invoke functions from referenced properties without having to deal with scoping issues.

It may also be good to think of a symbol for short-hand syntactic sugar for things such as item level, character level, target count.

Examples: $sl, &il, etc..

[Azurelol]

After the latest round of changes I believe it's in a good state. I will await your review.

[KSops]

I didnt look too deeply on testing it so if it works it works :)