Questioning the additional filtering done on the already-filtered RPC response
Hi!
I noticed this project is doing additional filtering on the output of the already-filtered `get_transfers` RPC call. See https://github.com/emesik/monero-python/blob/master/monero/backends/jsonrpc.py#L221

Some of the filtering seems redundant,  and some **messes with the result** you'd expect to get from the Wallet RPC.

Example: We have 1 unconfirmed incoming transaction, and lets say we're currently on the block 500.

If we ask the Wallet RPC for all the `in` and `pool` transactions where `min_height` is 500, we would see the unconfirmed transaction.
```bash
$ curl -X POST http://127.0.0.1:18082/json_rpc -d '{"jsonrpc":"2.0","id":"0","method":"get_transfers","params":{"in":true, "pool": true, "filter_by_height": true, "min_height": 500}}' -H 'Content-Type: application/json'
```

But if we ask the same to monero-python, we wouldn't see the unconfirmed transaction
```python
from monero.wallet import Wallet
from monero.backends.jsonrpc import JSONRPCWallet

wallet = Wallet(JSONRPCWallet(host='localhost', port=18082))
inc = wallet.incoming(unconfirmed=True, min_height=500)
```

And the problem stems from the post-filtering done [here](https://github.com/emesik/monero-python/blob/master/monero/backends/jsonrpc.py#L221). The unconfirmed Tx would fail to meet [this check](https://github.com/emesik/monero-python/blob/master/monero/transaction.py#L194), and be filtered out from the results

I'd suggest reviewing the need for checking every result against `PaymentFilter.check`