Add option to use query params for querying events

[banool]

Currently you have to construct a nasty event key yourself when using the API that looks like this:

0x000000000000000088fbd33f54e1126269769780feb24480428179f552e2313fbe571b72e62a1ca1

Really this is a concatenation of the creation number and account address.

Instead we should allow using query params, like ?creation_number=2&account_address=0x01