Partially replace the use of eth-lib

[spacesailor24]

We're making an effort to replace the usage of one-off libraries with official @ethereumjs libraries, and we're doing it one library at a time to reduce the chance of breaking changes

In this PR we're partially replacing the use of eth-lib, by updating the hashing methods, but keeping the methods used for account generation and signatures. We'll need to have further discussion around these since there's no replacement provided by @ethereumjs

[render]

Your Render PR Server URL is https://web3-js-pr-4390.onrender.com.

Follow its progress at https://dashboard.render.com/static/srv-c57t801t9dse23vff9t0.

[lgtm-com]

This pull request introduces 1 alert when merging dfa23a0 into 977f0f9 - view on LGTM.com

new alerts:

• 1 for Missing variable declaration

[coveralls]

Pull Request Test Coverage Report for Build 1274222255

• 3 of 9 (33.33%) changed or added relevant lines in 2 files are covered.
• 416 unchanged lines in 7 files lost coverage.
• Overall coverage decreased (-2.4%) to 72.545%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/web3-eth-accounts/src/index.js	1	3	33.33%
packages/web3-utils/src/utils.js	2	6	33.33%

Files with Coverage Reduction	New Missed Lines	%
packages/web3-core-requestmanager/src/jsonrpc.js	1	88.0%
packages/web3-core-helpers/src/formatters.js	23	81.4%
packages/web3-core-helpers/src/errors.js	31	4.41%
packages/web3-utils/src/soliditySha3.js	55	5.13%
packages/web3-utils/src/index.js	62	29.31%
packages/web3-utils/src/utils.js	83	12.86%
packages/web3-eth-accounts/src/index.js	161	23.77%

Totals
Change from base Build 1268465223:	-2.4%
Covered Lines:	3355
Relevant Lines:	4367

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💛 - Coveralls