docs: fix stale corepc-node references

[satsfy]

Follow up from #573 (comment)

Continues corepc-node to bitcoind rename.

This updates stale documentation references that were missed in earlier changes. It fixes the top level crate listing, the bitcoind crate README examples and text, the bitcoind/contrib/extra_tests.sh comments, and the integration_test README.

[tcharding]

Oh extra_test.sh is from the old CI setup, it can be deleted. As can crates.sh.

update-lock-files.sh can go too if the justfile is patched as well but that is kind of unrelated.

[tcharding]

I think that is the second time this week I've seen that CI fail. Re-ran it.

[jamillambert]

I have created the label C-bitcoind that the changes in this PR require.

All the docs changes look good. The deletion of extra_tests.sh, crates.sh and update-lock-files.sh and updating the justfile can be done here or a separate PR.

Reviewed a5e8d9b

[satsfy]

Thanks, looked more sensible to open a new PR for it #575

[jamillambert]

Can you swap the commit order, currently you "fix" extra_tests.sh then in the next commit delete it.

[satsfy]

Force push with the mentioned change, my oversight, thanks.