Add exports for AbstractProviderOptions and for MulticoinProviderPlugin.

Fix lost promise fulfillment when a batch has an error response (ethe…

…rs-io#4126).

Fix CJS browser bundling (ethers-io#4033).

Bump ens-normalize version (ethers-io#4071, ethers-io#4077, ethers-io…

…#4080, ethers-io#4102).

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).