Move Encoding class away from the Language namespace

Language\Encoding::__mbMimeEncode -> Convert\MimeEncode::__mbMimeEncode
Langauge\Encoding::checkConvertEncoding -> Check\Encoding::checkConvertEncoding
Langauge\Encoding::setErrorChar -> Check\Encoding::setErrorChar
Langauge\Encoding::getErrorChar -> Encoding::getErrorChar
Langauge\Encoding::convertEncoding -> Convert\Encoding::convertEncoding

Also fixed encoding check that not only a code point but a string can
also be used as a parameter.

Update phpunit tests and split them out for each class

Normal test page is still combined for all classes but updated to
correctly use each class

4dev/tests/CoreLibsCheckEncodingTest.php

@@ -0,0 +1,117 @@
+<?php
+
+declare(strict_types=1);
+
+namespace tests;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Test class for Check\Encoding
+ * @coversDefaultClass \CoreLibs\Check\Encoding
+ * @testdox \CoreLibs\Check\Encoding method tests
+ */
+final class CoreLibsCheckEncodingTest extends TestCase
+{
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function checkConvertEncodingProvider(): array
+	{
+		return [
+			// 0: string to test
+			// 1: source encoding
+			// 2: target encoding
+			// 3: substitue character
+			// 4: false for ok, array with error list
+			'valid test UTF-8 to SJIS (default)' => [
+				'日本語',
+				'UTF-8',
+				'SJIS',
+				null,
+				false
+			],
+			'invalid test UTF-8 to SJIS (dots as code point)' => [
+				'❶',
+				'UTF-8',
+				'SJIS',
+				0x2234,
+				['❶']
+			],
+			'invalid test UTF-8 to SJIS (dots as string)' => [
+				'❶',
+				'UTF-8',
+				'SJIS',
+				'∴',
+				['❶']
+			],
+			'invalid test UTF-8 to SJIS (none)' => [
+				'❶',
+				'UTF-8',
+				'SJIS',
+				'none',
+				['❶']
+			],
+			'invalid test UTF-8 to SJIS (long)' => [
+				'❶',
+				'UTF-8',
+				'SJIS',
+				'long',
+				['❶']
+			],
+			'invalid test UTF-8 to SJIS (entity)' => [
+				'❶',
+				'UTF-8',
+				'SJIS',
+				'entity',
+				['❶']
+			],
+		];
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @covers ::checkConvertEncoding
+	 * @dataProvider checkConvertEncodingProvider
+	 * @testdox check encoding convert from $from_encoding to $to_encoding [$_dataName]
+	 *
+	 * @param  string          $input
+	 * @param  string          $from_encoding
+	 * @param  string          $to_encoding
+	 * @param  string|int|null $error_char
+	 * @param  array|bool      $expected
+	 * @return void
+	 */
+	public function testCheckConvertEncoding(
+		string $input,
+		string $from_encoding,
+		string $to_encoding,
+		$error_char,
+		$expected
+	): void {
+		if ($error_char !== null) {
+			\CoreLibs\Check\Encoding::setErrorChar($error_char);
+			if (!in_array($error_char, ['none', 'long', 'entity'])) {
+				$this->assertEquals(
+					\IntlChar::chr($error_char),
+					\CoreLibs\Check\Encoding::getErrorChar()
+				);
+			} else {
+				$this->assertEquals(
+					$error_char,
+					\CoreLibs\Check\Encoding::getErrorChar()
+				);
+			}
+		}
+		$return = \CoreLibs\Check\Encoding::checkConvertEncoding($input, $from_encoding, $to_encoding);
+		$this->assertEquals(
+			$expected,
+			$return
+		);
+	}
+}
+
+// __END__