Error Catcher rewrite

[gdavid04]

Changes Error Catcher to have its own output instead of replacing the output of its target.

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This change would make Error Catchers easier to understand by making them work in a more intuitive way, while also giving advanced users and addon developers more options.

The same piece could have multiple Error Catchers attached to it, all of them completely independent from each other, unlike the current system which is limited to one per target. Addons could add pieces that provide more advanced error handling such as output whether an error occured somewhere.

TODO before merge:

• Use getter instead of SpellParam Subclass
• Don't set grid position of SpellRuntimeExceptions automatically when already set
• Make fallback optional (Error Catcher outputs nothing when fallback is not set, useful for tricks)