Cleanup SI Unit classes and interface for REST responses; fixes to a few METAR parsing issues

app/Support/Units/Pressure.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Support\Units;
+
+use App\Interfaces\Unit;
+use PhpUnitsOfMeasure\PhysicalQuantity\Pressure as PressureUnit;
+
+/**
+ * Composition for the converter
+ */
+class Pressure extends Unit
+{
+    public $responseUnits = [
+        'atm',
+        'hPa',
+    ];
+
+    /**
+     * @param float  $value
+     * @param string $unit
+     *
+     * @throws \PhpUnitsOfMeasure\Exception\NonNumericValue
+     * @throws \PhpUnitsOfMeasure\Exception\NonStringUnitName
+     */
+    public function __construct(float $value, string $unit)
+    {
+        $this->unit = setting('units.temperature');
+        $this->instance = new PressureUnit($value, $unit);
+    }
+}