Render paragraph and heading typography styles on front end

[MAILPOET-3007]

lib/Form/Block/Heading.php

@@ -80,6 +80,12 @@ class Heading {
     if (isset($block['params']['text_color'])) {
       $styles[] = 'color: ' . $block['params']['text_color'];
     }
+    if (!empty($block['params']['font_size'])) {
+      $styles[] = 'font-size: ' . $block['params']['font_size'] . 'px';
+    }
+    if (!empty($block['params']['line_height'])) {
+      $styles[] = 'line-height: ' . $block['params']['line_height'];
+    }
     if (!empty($block['params']['background_color'])) {
       $styles[] = 'background-color: ' . $block['params']['background_color'];
     }

lib/Form/Block/Paragraph.php

@@ -66,6 +66,9 @@ class Paragraph {
     if (!empty($block['params']['font_size'])) {
       $styles[] = 'font-size: ' . $block['params']['font_size'] . 'px';
     }
+    if (!empty($block['params']['line_height'])) {
+      $styles[] = 'line-height: ' . $block['params']['line_height'];
+    }
     if (empty($styles)) {
       return null;
     }

tests/unit/Form/Block/HeadingTest.php

@@ -91,4 +91,24 @@ class HeadingTest extends \MailPoetUnitTest {
     expect($html)->contains('style="background-color: red');
     expect($html)->contains('class="mailpoet-has-background-color"');
   }
+
+  public function testItShouldRenderFontSize() {
+    $html = $this->heading->render([
+      'params' => [
+        'content' => 'Header',
+        'font_size' => '33',
+      ],
+    ]);
+    expect($html)->equals('<h2 style="font-size: 33px">Header</h2>');
+  }
+
+  public function testItShouldRenderLineHeight() {
+    $html = $this->heading->render([
+      'params' => [
+        'content' => 'Header',
+        'line_height' => '2.3',
+      ],
+    ]);
+    expect($html)->equals('<h2 style="line-height: 2.3">Header</h2>');
+  }
 }

tests/unit/Form/Block/ParagraphTest.php

@@ -77,6 +77,16 @@ class ParagraphTest extends \MailPoetUnitTest {
     expect($html)->equals('<p class="mailpoet_form_paragraph" style="font-size: 33px">Paragraph</p>');
   }
 
+  public function testItShouldRenderLineHeight() {
+    $html = $this->paragraph->render([
+      'params' => [
+        'content' => 'Paragraph',
+        'line_height' => '2.3',
+      ],
+    ]);
+    expect($html)->equals('<p class="mailpoet_form_paragraph" style="line-height: 2.3">Paragraph</p>');
+  }
+
   public function testItShouldRenderDropCap() {
     $html = $this->paragraph->render([
       'params' => [