Option to skip hash validation and error message improvements

[r15ch13]

• Add show_app() function for displaying app/bucket@version
• Add option (-s | --skip) to skip hash validation on scoop install and scoop update to allow installation when a manifest provides an outdated hash
• Add new_issue_msg() function for nicer error messages with a link to the buckets repository. clicking on the link opens a new issue with a predefined title
• Show filename instead of unreadable robocopy output when file moving fails and use new_issue_msg()
• Handle hash validation errors with new_issue_msg()

Hm, maybe I put too much in this pull-request ... one change leads to another. 🤷‍♂️ 😁

Example output:

λ .\bin\scoop.ps1 install wox
Installing 'wox' (1.3.524) [64bit]
Wox-1.3.524-full.nupkg (5,0 MB) [===========================] 100%
Checking hash of Wox-1.3.524-full.nupkg... ERROR Hash check failed!
App:       extras/wox
URL:       https://github.com/Wox-launcher/Wox/releases/download/v1.3.524/Wox-1.3.524-full.nupkg#/dl.7z
Expected:  bfb73e46c3c054c00c24ab0f03ed441ab1308e07
Actual:    9025a4d5264b9cf73cd48a2679b91f1127e46c10

Please create a new issue by using the following link and paste your console output:
https://github.com/lukesampson/scoop-extras/issues/new?title=wox%401.3.524%3a+hash+check+failed

Ultimate goal: Use GitHub Issue API to find reported hash check errors and let Excavator resolve them automagically.

[rasa]

Perhaps:

throw "Could not find '$(fname $from)'! (error $lastexitcode)"

?

[brandon93s]

Very nice, I'm a fan of the issue links when an error occurs. 👍