Adds Livewire slack inputs

[Godmartinz]

Description

Updates the Slack Settings page to use Livewire.

• this removes SlackSettingsRequest.php since the rules have been moved over to the livewire controller.
• the ajax call from the API has been moved to the livewire controller as well.
• the PostSlack() method has been removed from the SettingsController.

On Integration test:

on bad name of channel:

on updating the slack settings:

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Test A
• Test B

Test Configuration:

• PHP version:
• MySQL version
• Webserver version
• OS version

Checklist:

• I have read the Contributing documentation available here: https://snipe-it.readme.io/docs/contributing-overview
• I have formatted this PR according to the project guidelines: https://snipe-it.readme.io/docs/contributing-overview#pull-request-guidelines
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[what-the-diff]

• Removed the slacktest function from SettingsController.php
• Added SlackSettingsForm livewire component to handle all of this logic now
• Created a new request for validation in Requests/SlackSettingsRequest (this is not used anymore)
• Updated Setting model with 3 new fields: slack_endpoint,slack_channel and slack_botname
• Removed the old slack settings form
• Added a new livewire component for the slack settings form

[marcusmoore]

There are some little things to change but overall 🤩

this is always good 😄

[snipe]

Nice work on this, @Godmartinz. I did a little cleanup here #12522. One thing I noticed is that the submit button doesn't get greyed out if the test fails. The the previous (non-livewire) version, IIRC, if the test failed, we didn't allow the form to be submitted.

There are really only two scenarios where that button should be enabled:

1. The test passed
2. The admin has removed ALL fields, effectively disabling slack integration.

Also the test button shouldn't appear until there are values for each field and the fields have passed the livewire validation.

I'll open a SC for you. :)