Co-authored-by: Jackson Mills <[email protected]>

Co-authored-by: Jackson Mills <[email protected]>

Co-authored-by: Jackson Mills <[email protected]>

Co-authored-by: Jackson Mills <[email protected]>

Co-authored-by: Jackson Mills <[email protected]>

This will reduce the bundle size by ~23%(117kb).

Only 4 methods were used `flatten`, `flatMap`, `omitBy`, and `groupBy`.

`omitBy and `groupBy` were recreated while the es2019 implementations of
`flatten` and `flatMap` are used.

`lodash` is still used in the tests which is fine because it makes the
tests cleaner.

Closes #2118

Reduces the bundle size by 8% (41kb)

BigInteger is now well supported so the library is no longer needed.

BigNumber was already being used by xrpl and they had almost identical
interfaces as they are both based on Java.

Bump https-proxy-agent to v7 and a dev dependency. This makes
configuring bundlers easier to configure and removes a direct
dependency of `https-proxy-agent`.

BREAKING CHANGE: Configuring a proxy is done by specifying the
`agent` parameter on the ConnectionOptions config. This can use be
created by libraries such as `https-proxy-agent` or any that
implements `http.Agent`.

Switch to using fetch for browser and `node-fetch` for node for the faucet calls.  This reduces the webpack bundle by 3.2% or 16.5kb gzipped.

The fundWallet code has been refactored to be much more straight forward due to not having to do such low level operations.

This improves the frontend setup process by no longer requiring several polyfills such as `url`, `stream-http`, and `https-browserify`.

Use if statements and manually error throwing to save 20kb gzipped.

BREAKING CHANGE: If you were catching AssertionError you need to change to Error.

BREAKING CHANGE: `BroadcastClient` was removed. It was deprecated in 2.2

…eing specified (#2376)

* Fix assertion

* Add a test