Reduce console log spam (#3896)

* Reduce console log spam

A couple of different things:

 * Increase the `MaxListeners` setting on `MatrixClient` and `Thread`, so that
   we don't get "possible EventEmitter leak" warnings

 * Disable a couple of warnings/info lines that are just part of regular
   operation and are logged in large volumes.

* another noisy log line

* Reinstate warning about receipts for missing events

Apparently this is being worked on

src/rust-crypto/rust-crypto.ts

@@ -1560,10 +1560,6 @@ class EventDecryptor {
     ) {}
 
     public async attemptEventDecryption(event: MatrixEvent): Promise<IEventDecryptionResult> {
-        this.logger.info(
-            `Attempting decryption of event ${event.getId()} in ${event.getRoomId()} from ${event.getSender()}`,
-        );
-
         // add the event to the pending list *before* attempting to decrypt.
         // then, if the key turns up while decryption is in progress (and
         // decryption fails), we will schedule a retry.