Add Jetpack integration loader, add the way to load config in local dev env

[rinatkhaziev]

Description

There are two things happening:

Added JetpackIntegration class - very basic, but it does set up the version respecting both integrations or the legacy way.

Added ability to override config values via two filters:

apply_filters( 'vip_integrations_config_file_path', $config_file_path_orig, $slug );

This one allows us to override the file path in non-VIP environments (dev env/Codespaces)

apply_filters( 'vip_integrations_pre_load_config', null, $config_file_path, $slug );
Following core WP pattern, adding the pre_ filter will short-circuit the prod logic and will allow to inject the values as needed.

Changelog Description

Pre-review checklist

Please make sure the items below have been covered before requesting a review:

• This change works and has been tested locally or in Codespaces (or has an appropriate fallback).
• This change works and has been tested on a sandbox.
• This change has relevant unit tests (if applicable).
• This change uses a rollout method to ease with deployment (if applicable - especially for large scale actions that require writes).
• This change has relevant documentation additions / updates (if applicable).
• I've created a changelog description that aligns with the provided examples.

Pre-deploy checklist

• VIP staff: Ensure any alerts added/updated conform to internal standards (see internal documentation).

Steps to Test

1. Add integrations.json into the root of dev env project with the following content:

{
	"jetpack": {
		"status": "enabled",
		"config": {
			"version": "14.0"
		}
	},
	"parsely": {
		"status": "disabled",
		"config": {
			"apikey": "myexampledomain.test"
		}
	}
}

2. In jetpack.php comment out the call to vip_jetpack_load
3. Refresh a page and verify that Jetpack is indeed loaded.
4. Flip the status and verify Jetpack is not loaded anymore.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud