Bug 240531

When I run `git webkit pr`, I get a lot of output from git that's super mysterious, as I don't get to see what command it's running. I think that we need to do something along the lines of:
- only have manually written high level descriptions of steps that can be long;
- when anything fails, then print both the command and its full output;
- in verbose mode, print all commands, but perhaps only print output on failure.

Here is what I get now:

git webkit pr
'main' is not a pull request branch, enter issue URL or title of new issue: Clearly recommend checking out from GitHub using https
[a lot of interactive questions about creating a new bug, which is OK]
Created 'https://bugs.webkit.org/show_bug.cgi?id=240528 Clearly recommend checking out from GitHub using https'
Switched to a new branch 'eng/Clearly-recommend-checking-out-from-GitHub-using-https'
Created the local development branch 'eng/Clearly-recommend-checking-out-from-GitHub-using-https'
Branch 'main' set up to track remote branch 'main' from 'origin'.
  Running status to find changed, added, or removed files.
  Reviewing diff to determine which lines changed.
  Extracting affected function names from source files.
  Change author: Alexey Proskuryakov <ap@apple.com>.
[eng/Clearly-recommend-checking-out-from-GitHub-using-https 29a8234baa3a] Clearly recommend checking out from GitHub using https https://bugs.webkit.org/show_bug.cgi?id=240528
 Date: Tue May 17 11:01:47 2022 -0700
 1 file changed, 6 deletions(-)
remote: Enumerating objects: 595, done.
remote: Counting objects: 100% (595/595), done.
remote: Compressing objects: 100% (321/321), done.
remote: Total 595 (delta 244), reused 545 (delta 208), pack-reused 0
Receiving objects: 100% (595/595), 3.78 MiB | 3.48 MiB/s, done.
Resolving deltas: 100% (244/244), completed with 39 local objects.
From https://github.com/WebKit/WebKit
   f93de9299d06..086f8badb578  main       -> main
   f93de9299d06..086f8badb578  main       -> origin/main
From https://github.com/WebKit/WebKit
 * branch                      main       -> FETCH_HEAD
Successfully rebased and updated refs/heads/eng/Clearly-recommend-checking-out-from-GitHub-using-https.
Rewrite 23256d046211f9bc3fb2dcdad6ff67cf98726b84 (1/1) (0 seconds passed, remaining 0 predicted)    
WARNING: Ref 'refs/remotes/origin/main' is unchanged
Ref 'refs/heads/eng/Clearly-recommend-checking-out-from-GitHub-using-https' was rewritten
Downloading pycodestyle-2.5.0...
Installing pycodestyle-2.5.0...
Installed pycodestyle-2.5.0!
Total errors found: 0 in 0 files
Enumerating objects: 5, done.
Counting objects: 100% (5/5), done.
Delta compression using up to 8 threads
Compressing objects: 100% (3/3), done.
Writing objects: 100% (3/3), 402 bytes | 201.00 KiB/s, done.
Total 3 (delta 2), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (2/2), completed with 2 local objects.
remote: 
remote: Create a pull request for 'eng/Clearly-recommend-checking-out-from-GitHub-using-https' on GitHub by visiting:
remote:      https://github.com/aproskuryakov/WebKit/pull/new/eng/Clearly-recommend-checking-out-from-GitHub-using-https
remote: 
To https://github.com/aproskuryakov/WebKit.git
 * [new branch]                eng/Clearly-recommend-checking-out-from-GitHub-using-https -> eng/Clearly-recommend-checking-out-from-GitHub-using-https
Total 0 (delta 0), reused 0 (delta 0), pack-reused 0
To https://github.com/aproskuryakov/WebKit.git
   23bb2191c39d..086f8badb578  main -> main
Created 'PR 680 | Clearly recommend checking out from GitHub using https'!
Posted pull request link to https://bugs.webkit.org/show_bug.cgi?id=240528
https://github.com/WebKit/WebKit/pull/680

Most of this is entirely useless in success case, and it's not great logging for failure case anyway.