Migrate browser folder files to typescript & fix npm build

[cgewecke]

#148

NB: PR targets #153

PR

• ports thebrowser/ file set to TS and aligns with new typescript config from Upgrade to @ethereumjs/config-typescript #152
• "fixes" the webpack build
• adds a build step to CI

RlpxPeer depends on two Node platform modules which aren't available in the browser: net and dgram. These probably need to be resolved to some alias.

Have configured webpack to ignore that problem for the moment so npm run build runs in some fashion for the monorepo transition.

#108 advises that we add a basic test to check the browser build, perhaps we can address whether or not the bundle is valid as part of that.

[coveralls]

Coverage increased (+0.1%) to 76.297% when pulling dcf1dab on fix/browser-build into f774a4b on master.

[holgerd77]

Side question for my understanding (and since I would find it pretty interesting to apply as well: does this "NB: PR targets..." trigger this "Base automatically changed" message or does this always happen if one targets another branch than master and the branch gets merged? 🤔

Haven't worked in such a branch cascade before but am constantly battling with similar situations...

[holgerd77]

Looks good.

[holgerd77]

Oh yeah, super useful

[cgewecke]

@holgerd77

Side question for my understanding (and since I would find it pretty interesting to apply as well: does this "NB: PR targets..." trigger this "Base automatically changed" message or does this always happen if one targets another branch than master and the branch gets merged?

Good question! - it's definitely new right?

Just made the notes for clarity and think this must be the correct explanation:

if one targets another branch than master and the branch gets merged