Add skar data source

[ozgrakkurt]

Hey!

Nice project, I am also building an indexer which indexes all ethereum historical data (blocks, logs, transactions, receipts). It has a fast api to query by addresses, topics etc. It can scan the entire mainnet history in 3 seconds for a couple addresses.

Currently there is a free endpoint for ethereum mainnet, it is documented here: https://github.com/data-indexing/skar

Would you be interested in adding it as a data source to SolidQuery?