fix: Correctly validate enum values in eq, neq and in methods

[kamilogorek]

I believe that when TypeScript resolves overloads, it squashes our 2 variants together, as they are not specific enough to be made distinct. I'm not exactly sure why it doesn't always favor the "more specific" type, but it is what it is.

Second overload can be squashed down into a single one, making overloads unnecessary at all and we can express the type definition directly in the implementation.

(we can also unify most if not all filters using this syntax, but it's your call and I didn't want to make this PR unnecessarily big)

Here's test playground for the issue:

https://www.typescriptlang.org/play/?ssl=15&ssc=1&pln=16&pc=1#code/PTAEFpNAhAlB5A0gUQHIFgBQWAuBPABwFNRYB7Ad1AF5QBvLUUASwBMAuUAZxwCdmAdgHMANI1C8yAGyKcA5AEEAIgFkAkqjmgAPqDkBVAMrJYcrAF8sWAGYBXAQGMczMgJZdyMgIq2ivPAA8AMLStgC2AqgAhmEkRAAeOEQCrFzcfIJCoABkoADWRHhk1qSUAHwAFOIOoRGcIVLhkTFEYphMAG5RjbKgqK6otlJSUQBGMgHkFADaDU3RsQC6ZVgAlJw8-MIA3Db2Ti5uzB7SRD5+gQBq3b6gCUkpafZ5ApQClTWNdelboqBdPU4-UiQxG4yIAWuPTK6x+mV2mDsjmcrncnjOvn8FU+TQ2GWEIn+N16z1eFAEsM2mXo1VcPG4RCivAcAAsAApMmJpWgCIhUfSwAAyhkZzPZnLCXAqq3EXFFrI5vC5ADoogRiClsbUBISAAa8gCOyoAJHQAb5zLqZe0JEQcLZeG45UyFRKuMqcGRDPihNKLFZMMd0ecsXJJDI5IS5BQWVEkh0-AB9ChkXh5Lhya1YEAQKAAMTUAA1kEoA-hiKB4DgWX4pjQaTa2Hjfm0mOHeopVBotLoDMZTP7sIj9iijidvJi8HnmPEiKxgtqFnFEslUnDhJVxEwcd85hEl62mETAaA981YncV498oVipXq7XKKAAPz3mu8KazRctRagTikt5KR9BttzpHAGRdcUlUleteX5IURUgxUuT9G1nTFZDJVVdVVy1L4dVAfUiCNU1zSIS1rTbO0HSdeUoJVT1vV+VDLCHINThDKcZznCow1OSM9BjOMiATXhk1TdNMywdiJwuadZ1YXj2wEzt1E0VYgA

[kamilogorek]

The only thing I'm curios about is if we ever allowed for .eq<'number'>('id', 42) for example 🤔