Improve errors in logs

[bwmarkle]

1. Include a "friendly notice" that says this is the last error found by php, but it doesn't necessarily mean it was triggered by the backup plugin, or that the backup failed
2. We should add descriptions for the error numbers so it's easier to see it was a fatal or just a warning

boldgrid-backup/admin/class-boldgrid-backup-admin-log.php

Lines 131 to 148 in 4d7437d

	/**
	* Add the last error to the log.
	*
	* The error is only added to the log if it hasn't been logged before.
	*
	* @since 1.13.5
	*/
	public function add_last_error() {
	$current_error = error_get_last();
	// Only new errors are logged.
	if ( $current_error !== $this->last_error ) {
	$this->add( 'Last error: ' . print_r( $current_error, 1 ), false ); // phpcs:ignore
	}
	// This method will be called often, so keep track of errors to avoid logging duplicates.
	$this->last_error = $current_error;
	}

Maybe add "type description" below.

[2023-03-21 09:51:23 UTC] Last error: Array
(
[type] => 8
[type_description] => 'E_NOTICE (int) - Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.',
[message] => mysqli_query(): send of 4852 bytes failed with errno=104 Connection reset by peer
[file] => /home/user/public_html/wp-includes/class-wpdb.php
[line] => 2187
)