[Performance Issue]: PollingBlockTracker is instantiated with too high pollingInterval

Nobody has claimed this yet.

### Describe the bug

MetaMask keeps a cache of request/response in order to minimize the calls to the RPC endpoint, but its refresh interval is set too high even for the Ethereum blockchain, let alone other EVM-compatible blockchains with sub-second block creation time.

The PollingBlockTracker cache is instantiated with the default pollingInterval value that is set to 20 seconds:
https://github.com/MetaMask/metamask-extension/blob/7226357422d727cb10b42e749eb3e9b47adaaa4c/app/scripts/controllers/network/createJsonRpcClient.js#L22

https://github.com/MetaMask/eth-block-tracker/blob/c83a963aac367e9820126d7d5a544044741e0b10/src/PollingBlockTracker.ts#L45

The result is that block creations are detected much later than they actually happened, with the consequence that transaction confirmations and event logs are delayed, ruining the user experience.

For the transaction confirmation there is a workaround, it's possible to manually poll the `eth_getTransactionReceipt` function that bypass the cache and also allow MetaMask to detect a block change faster, as soon as the receipt with a more recent block number is returned. But for the event logs I haven't found a workaround yet.

It'd be very useful if the default polling interval was set to a more sane value (5 seconds?), and perhaps overridable from the MetaMask network configuration (and the related API to add a network to MM).

### Steps to reproduce

1. Connect to a network with sub-second block finality
2. Call the `eth_blockNumber` (or submit a transaction, or listen to events)

### Error messages or log output

_No response_

### Version

10.8.2

### Build type

_No response_

### Browser

Chrome, Firefox

### Operating system

Windows, MacOS, Linux

### Hardware wallet

_No response_

### Additional context

_No response_

Read app/scripts/controllers/network/createJsonRpcClient.js at the linked construction and eth-block-tracker/src/PollingBlockTracker.ts around the default pollingInterval. Reproduce with eth_blockNumber on a sub-second network; done means the tracker interval is no longer fixed at 20 seconds and can be overridden through network configuration, reducing delayed block and event updates.

Written by the indexing model from the issue text.