upgrade web3 package

[donnyquixotic]

Fixes #430 #431

Description

• Upgrades web3 version from 1.x to 4.x
• Fixes sourcify link in generic contract template
• Updates README and include note about updated required Node version
• Updates CI yaml node version

Test scenarios

1. Contract interaction should be consistent with deploy previews in made contract instance raw so we can access properties #419
2. 'Click Here' link should redirect to sourcify for unverified contracts

Note

• this includes a new required Node version 16

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have cleaned up the code in the areas my change touches
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings
• I have removed any unnecessary console messages

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Pages

Latest commit:	d04dc8c
Status:	✅  Deploy successful!
Preview URL:	https://2a2352d9.teloscan.pages.dev
Branch Preview URL:	https://430-upgrade-web3-package.teloscan.pages.dev

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