fix: remove node.js Buffer for better browser compatibility

[luizstacio]

When using on browser env's, Buffer is not available, requiring extra bundler configs with polyfills. Using stringFromBuffer from the Keystore package, it's possible to use Buffer on node env's and TextDecoder on browsers. Fixing the issue.

For now, we don't have a CI for automating the tests on browser #284. Because of this, I have tested it locally this are the following steps;

1. On this branch
2. Inside packages/keystore run pnpm build and pnpm link --global --dir .
3. Create an react app using npx create-react-app my-test-app
4. Inside the app my-test-app run pnpm link --global @fuel-ts/keystore
5. On the src/App.js file, paste the following code right after import './App.css';

import { decrypt, encrypt } from '@fuel-ts/keystore/dist';

const data = {
  'foo': 'bar'
};

encrypt('password', JSON.stringify(data)).then((encrypted) => {
  decrypt('password', encrypted).then((decrypted) => {
    console.log(JSON.parse(decrypted));
  });
});

6. The console.log should show the correct data, after encrypting and decrypting.

Notes: the /dist at @fuel-ts/keystore/dist is only needed because we are using pnpm link

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟢	Statements	91.07% (-0.06% 🔻)	3834/4210
🟡	Branches	74.07% (-0.5% 🔻)	740/999
🟢	Functions	88.01% (-0.09% 🔻)	749/851
🟢	Lines	91.1% (-0.07% 🔻)	3676/4035

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / keystore.ts	100%	50%	66.67% (-8.33% 🔻)	100%
🔴	... / aes-ctr-web.ts	23.08% (-0.92% 🔻)	100%	0%	23.08% (-0.92% 🔻)
🟡	... / script.ts	79.31% (-3.45% 🔻)	50% (-12.5% 🔻)	83.33%	79.31% (-3.45% 🔻)
🟢	... / errors.ts	100%	50% (-33.33% 🔻)	100%	100%
🟢	script/src/utils.ts	88.89% (-11.11% 🔻)	60%	100%	87.5% (-12.5% 🔻)

Test suite run success

596 tests passing in 62 suites.

Report generated by 🧪jest coverage report action from 5194510