I'd like to right click on a machine and see the Capabilities installed, like if it has RSAT, additional languages, etc.

Info can be grabbed via PowerShell or Registry.

This is NOT available in CM Database, or WMI

Registry:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\CapabilityIndex

PowerShell:

$InstalledCapabilities = (Get-WindowsCapability -Online | Where-Object {$_.State -eq "Installed"}).Name

ForEach ($InstalledCapability in $InstalledCapabilities){($InstalledCapability).split("~~~~")[0]}