Verify integrity of already installed resources

Summary of the new feature / enhancement

Would be cool with the ability to verify the integrity of already installed resources, also if they aren't signed. As in, make sure no changes has been made to the <ModuleName>\<ModuleVersion> directory and all its' content.

Proposed technical implementation details (optional)

Cmdlet:

• On scope: Verify-PSResource -Name '<name>' -Version '<version>' -Scope '<AllUsers|CurrentUser>'
• With path: Verify-PSResource -Path 'C:\some\path\<ModuleName>\<ModuleVersion>'

Options/logic:

• Create some comparison logic that checks that all files are present (and no other files are added) with correct checksum?
• If any file is changed, added or is missing, nuke the directory and install it fresh with a switch -Remediate.
• If no PS info XML file is found, require parameter -Repository to be specified in the cmdlet.

Start at the proposed Verify-PSResource cmdlet entry point and review how installed resources and their <ModuleVersion> directories are represented. Define verification for missing, added, or changed files, including the unsigned-resource and -Repository cases; done means the command reports integrity and -Remediate reinstalls when requested.