Cache user API call for 5 minutes

[remyperona]

Description

Cache the user API call for 5 minutes to avoid the request on each page load.

Type of change

• Bug fix (non-breaking change which fixes an issue).

Detailed scenario

• With current develop, using query monitor, you can see there is a request to https://app.imagify.io/api/users/me/ on every page load
• Using this PR branch, the request happens once, and should not happen again for 5 minutes

Technical description

Documentation

Following changes made in #899, #900, #902, the User class is used on more pages than before, and this class makes an API call to get the user information, with a timeout of 10 seconds.

Caching the result of the API call allows to prevent the request on every page.

It was not possible to use the existing imagify_get_cached_user() function, because this function returns a cache that doesn't match the result from the API call, but a result from the cache of the User class itself.

Mandatory Checklist

Code validation

• I validated all the Acceptance Criteria. If possible, provide screenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.

Code style

• I wrote a self-explanatory code about what it does.
• I protected entry points against unexpected inputs.
• I did not introduce unnecessary complexity.

[wordpressfan]

@Tabrisrp
Do u know what is the difference between this PR and the code found here:

imagify-plugin/inc/functions/admin.php

Lines 391 to 424 in 5684433

	/**
	* Cache Imagify user data for 5 minutes.
	* Runs every methods to store the results. Also stores formatted data like the quota and the next update date.
	*
	* @since 1.7
	*
	* @return object|bool An object on success. False otherwise.
	*/
	function imagify_cache_user() {
	if ( ! Imagify_Requirements::is_api_key_valid() ) {
	return false;
	}
	$user = new User();
	$data = (object) get_object_vars( $user );
	$methods = get_class_methods( $user );
	foreach ( $methods as $method ) {
	if ( '__construct' !== $method ) {
	$data->$method = $user->$method();
	}
	}
	$data->quota_formatted = imagify_size_format( $user->quota * pow( 1024, 2 ) );
	$data->next_date_update_formatted = date_i18n( get_option( 'date_format' ), strtotime( $user->next_date_update ) );
	if ( imagify_is_active_for_network() ) {
	set_site_transient( 'imagify_user', $data, 5 * MINUTE_IN_SECONDS );
	} else {
	set_transient( 'imagify_user', $data, 5 * MINUTE_IN_SECONDS );
	}
	return $data;
	}

Now we inroduce a transient called imagify_user_cache and there is another one called imagify_user

if it's OK to introduce this transient, should we update the data being saved to have those attributes?

imagify-plugin/inc/functions/admin.php

Lines 414 to 415 in 5684433

	$data->quota_formatted = imagify_size_format( $user->quota * pow( 1024, 2 ) );
	$data->next_date_update_formatted = date_i18n( get_option( 'date_format' ), strtotime( $user->next_date_update ) );

[remyperona]

I explained it in the technical description, they're not exactly the same data. One is caching the API call itself, the other is caching the User class.

Ideally we would implement things differently, but it would require too much work right now.

[Mai-Saad]

On PR => refresh admin won't send API call to imagify till this transient is expired imagify_check_api_version
On trunk => API call is there with every refresh