Move AGLint comment parser into the AGLint codebase

Currently, AGTree is able to parse AGLint comments. However, for this, AGTree requires an external library, json5, to parse configuration objects, such as this:

```adblock
! aglint "rule-1": ["warn", { "option1": "value1" }], "rule-2": "off"
```

I suggest that, for the optimal operation of AGTree, we move this logic into AGLint, as it is only relevant there.