Incomplete contract filters typing

`ethers` allows to filter using arrays for each event argument, for example:

```ts
erc20.filters.Transfer(null, [addr1,addr2]
```
But this doesn't work with Typechain since the typing for the `Transfer` filter is something like this:

```ts
Transfer(from?: PromiseOrValue | null , to?: PromiseOrValue | null, value?: null): TransferEventFilter
```