Use consistent capitalization for (Script)PubKey

[jamillambert]

The capitalization of key in pubkey and scriptpubkey is inconsistent. Core uses a capital K in e.g. scriptPubKey in gettxout, and a capital K is more common in rust-bitcoin.

Search the whole codebase for "Pubkey" and change them all to "PubKey". No changes made where the p is lowercase.

Closes #371

[tcharding]

ACK abd9f78

[tcharding]

I'm surprised the linter doesnt' complain about this? If it starts doing so I'm inclined to think we should just use 'pubkey' and 'Pubkey' (capitalized) in docs and not add an attribute to shoosh the linter.

[tcharding]

Weird, the merge script just started erroring even though I only just merged #519 with it.

emote: Resolving deltas: 100% (57/57), completed with 40 local objects.
remote: error: GH013: Repository rule violations found for refs/heads/master.
remote: Review all repository rules at https://github.com/rust-bitcoin/corepc/rules?ref=refs%2Fheads%2Fmaster
remote: 
remote: - Changes must be made through a pull request.
remote: 
To github.com:rust-bitcoin/corepc
 ! [remote rejected]   master -> master (push declined due to repository rule violations)
error: failed to push some refs to 'github.com:rust-bitcoin/corepc'
Traceback (most recent call last):
  File "/home/tobin/bin/github-merge", line 495, in <module>
    main()
  File "/home/tobin/bin/github-merge", line 487, in main
    subprocess.check_call([GIT,'push',host_repo,'refs/heads/'+branch])
  File "/usr/lib/python3.12/subprocess.py", line 413, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['git', 'push', 'git@github.com:rust-bitcoin/corepc', 'refs/heads/master']' returned non-zero exit status 1.

Going to click the button and leave in case GitHub is just gliching out right now.