Fixed AbstractProvider lookupAddress bug (ethers-io#4086).

Coerce value into BigInt when checking for value.

Added support for legacy ABI JSON fragments (ethers-io#3932).

Fixed events when emitted in WebSocketProvider (ethers-io#3767, ether…

…s-io#3922).

Fixed FetchRequest when using credentials (ethers-io#3897).

Stall block polling bootstrap when the network is down (ethers-io#3924).

Added extra details in the error info field for RPC errors.

Fixed ethers imported in web workers (ethers-io#3856).

Fix matic-mumbai network and include aliases to legacy names (ethers-…

…io#3811).

Fixed getContentHash (ethers-io#3819).