parseDestScript improvements & new features

[Toma400]

Here is the list of new features or improvements that should be implemented in near future - including the obvious thing that is making parseDestScript[...] function somehow separate (it is currently nested).

Inventory support

Obvious and of course something I'm working on, but scripts should be able to use inventory. I have some refactoring idea in mind that will automatically allow 2/3 of inventory cases to work, but still the remaining 1/3 (non-stackable items) should have special treatment. This may be helpful in the future, if any list-like files will appear again (probably it will be containers or NPCs).

Better support for data type differentiation, support for floats and booleans

Currently, the support for ints was added as one of the last-second measures to not make saves corrupted by overwriting them with string data type - so it's very barebones.
Ideally, scripts should allow strings be explicit by use of "" and ints/floats/bools be converted.

"Check if key exists" - especially useful for inventory

There's currently no way to check if key exists or do the check no matter if something exists. Both would be useful honestly - either to check if key exists at all (and this behaviour defaulting to basically >0 being False) and skipping the key error if you check for any other number.
There are two situations when this can happen, however:

• inventory - where ideally the behaviour should skip key error and behave as if item was 0
• stats - where missing key could be more important error and could require at least log message, or even whole crash (it can be prevented by all stats and dependency checks, but some way of handling it should exist)