Support line breaks and tab replacement in tabular table values

This adds the same functionality from both #179 and #181 to the tabular
table output. In WP CLI behat tests, the 'table containing rows' check
can only use tabular output so we need to fix it here in order for tests
to work.

lib/cli/table/Tabular.php

@@ -22,7 +22,30 @@ class Tabular extends Renderer {
 	 * @param array  $row  The table row.
 	 * @return string  The formatted table row.
 	 */
-	public function row(array $row) {
-		return implode("\t", array_values($row));
+	public function row( array $row ) {
+		$rows   = [];
+		$output = '';
+
+		foreach ( $row as $col => $value ) {
+			$value       = str_replace( "\t", '    ', $value );
+			$split_lines = preg_split( '/\r\n|\n/', $value );
+			// Keep anything before the first line break on the original line
+			$row[ $col ] = array_shift( $split_lines );
+		}
+
+		$rows[] = $row;
+
+		foreach ( $split_lines as $i => $line ) {
+			if ( ! isset( $rows[ $i + 1 ] ) ) {
+				$rows[ $i + 1 ] = array_fill_keys( array_keys( $row ), '' );
+			}
+			$rows[ $i + 1 ][ $col ] = $line;
+		}
+
+		foreach ( $rows as $r ) {
+			$output .= implode( "\t", array_values( $r ) ) . PHP_EOL;
+		}
+
+		return trim( $output );
 	}
 }