Reduce bundle size

[rolznz]

From hzrd149/nostrudel#11

Currently we depend on nostr-tools and some other packages, which are more bloated than necessary. We might be able to replace these with more cut-down versions or implement the code ourselves.

This will get worse when we add further integrations which require their own packages such as LNC.

[rolznz]

Main issues:

• Remove source maps (this is >3MB of wasted space)
• Remove browserify/esbuild index.browser.js files

The above need to be done in Bitcoin Connect, alby JS SDK and lightning tools.

[rolznz]

We can upload the browserify builds to the release instead.

But actually something like skypack should be used? #85

[rolznz]

Currently the package size is 6.04MB. We should try to get it less than 1MB.