Use Pf4ConfirmationDialog widget to delete airgun entities

[jameerpathan111]

Fix existing Airgun code for entities which use new confirmation dialog(Pf4ConfirmationDialog) based on PF4, which is used for deleting entities.
See #649 and #652 for more info.

List of UI entities using new confirmation dialog.

• Hosts
• scap content
• Architectures
• Hardware models
• Installation Media
• Operating Systems
• Job Templates
• Provisioning Templates
• Partition Tables
• Compliance Policies
• Host Groups
• Global Parameters
• Discovery Rules
• Ansible Roles
• Ansible Variables
• Capsules
• Compute Profiles
• Compute Resources
• Virt-who Configurations
• Http proxy
• Domains
• Subnets
• Realms
• Locations
• Organizations
• Users
• User Groups
• Authentication Sources
• Roles
• Bookmarks
• Webhooks
• Webhook Templates

[mshriver]

I've engaged with the UXD team (@Ron-Lavi) and @latran about this PF4 confirmation dialog (which is actually a modal).

This should be addressed not individually on entity views, but within the get_alert browser method defined in wt.core.

Either UXD team will modify the modal component to be recognized as a JS alert, or we'll override the core widgetastic browser method so that it can find the the modal when looking for alerts.

[mshriver]

Following discussion with UX, they're not going to be able to 'spoof' the browser alert for the new confirmation dialog modals.

This means we need to address this by implementing a custom Brower.get_alert function that can identify not only JS alerts, but confirmation modals.

airgun/airgun/browser.py

Line 258 in 12c4698

class AirgunBrowser(Browser):

https://github.com/RedHatQE/widgetastic.core/blob/7b228874bdbdbe7dc29436cff718bf8ce34b7e30/src/widgetastic/browser.py#L919

AirgunBrowser.get_alert should be implemented, in order to override the functionality of Browser.get_alert in the base class.

get_alert is the basis for several other functions within the browser, and the overridden method should be compatible with them, returning an element that dismiss, send_keys, accept, and text can be called against.

This will restore the behavior of handle_alert kwargs and browser functions, and our direct calls to view.dialog can be replaced with browser.handle_alert() calls.