eslint: (Mostly) synchronize configuration with gjs

In addition to the changes in this commit, gjs now restricts the use of the Format module and initFormat. We can't really replace those for translatable strings until xgettext gains support for template strings, so leave that bit out for now.

The other notable change is that gjs now requires jsdoc comments. We can't plainly enable those options without a massive amount of work first, but let's see how requiring doc comments for new code goes.