Minor schema cosmetic code fixes, more Attribute implementation from old pla, start of LDAP DN view/edit

app/Classes/LDAP/Attribute/Schema.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace App\Classes\LDAP\Attribute;
+
+use Illuminate\Support\Arr;
+use Illuminate\Support\Facades\Cache;
+
+use App\Classes\LDAP\Attribute;
+
+/**
+ * Represents an attribute whose values are schema related
+ */
+abstract class Schema extends Attribute
+{
+	protected bool $internal = TRUE;
+
+	protected static function _get(string $filename,string $string,string $key): ?string
+	{
+		$array = Cache::remember($filename,86400,function() use ($filename) {
+			try {
+				$f = fopen($filename,'r');
+
+			} catch (\Exception $e) {
+				return NULL;
+			}
+
+			$result = collect();
+
+			while (! feof($f)) {
+				$line = trim(fgets($f));
+
+				if (! $line OR preg_match('/^#/',$line))
+					continue;
+
+				$fields = explode(':',$line);
+
+				$result->put($x=Arr::get($fields,0),[
+					'title'=>Arr::get($fields,1,$x),
+					'ref'=>Arr::get($fields,2),
+					'desc'=>Arr::get($fields,3,__('No description available, can you help with one?')),
+				]);
+			}
+			fclose($f);
+
+			return $result;
+		});
+
+		return Arr::get(($array ? $array->get($string) : []),$key);
+	}
+}