Quoted string keys in record-literal types behave inconsistently

Example:
```js
var /** {'a': number} */ foo;
```

`JSDocInfoParser` creates a JSDoc AST with a STRING_KEY node whose `getString()` returns the string "`'a'`", *with the single quoted included*. A number of spots in the compiler explicitly remove these quotes (OTI's JSTypeRegistry and NTI's JSTypeCreatorFromJSDoc - search for "startsWith") before doing anything with the names, though it's not entirely consistent, since JSTypeCreatorFromJSDoc passes the STRING_KEY node to GlobalTypeInfo#recordPropertyName which gets the string but does not remove the quotes, to store it in allPropertyNames and/or externPropertyNames.

Ideally we should normalize these as early as possible. As far as I'm aware, the compiler does not behave any differently if a property name in a record literal is quoted, but if we needed to, we should instead add an annotation on the node and strip the quotes before storing the node's string. That said, I don't know what we would do differently, so maybe we can forgo that and just ignore the quotes completely?