Pontoon: Update Arabic (ar) localization of Thunderbird

Co-authored-by: Yasser Althuwaini <ymth2000@outlook.com>

ar/calendar/calendar/calendar-today-pane.ftl

@@ -0,0 +1,12 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at http://mozilla.org/MPL/2.0/.
+
+calendar-today-pane-show-events-and-tasks =
+    .tooltiptext = أظهر الأحداث والمهام
+calendar-today-pane-show-tasks-only =
+    .tooltiptext = أظهر المهام
+calendar-today-pane-show-events-only =
+    .tooltiptext = أظهر الأحداث
+calendar-today-pane-close-button =
+    .tooltiptext = أخْفِ لوحة اليوم

ar/mail/branding/tb_beta/brand.dtd

@@ -0,0 +1,13 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!ENTITY  brandShortName        "Thunderbird بيتا">
+<!ENTITY  brandShorterName      "Thunderbird بيتا">
+<!ENTITY  brandFullName         "Mozilla Thunderbird بيتا">
+<!-- LOCALIZATION NOTE (brandProductName):
+   This brand name can be used in messages where the product name needs to
+   remain unchanged across different versions (Daily, Beta, etc.). -->
+<!ENTITY  brandProductName      "Thunderbird">
+<!ENTITY  vendorShortName       "Mozilla">
+<!ENTITY  trademarkInfo.part1   "موزيلا Thunderbird وشعارات Thunderbird
+                                 علامات تجارية لمؤسسة Mozilla.">

ar/mail/branding/tb_beta/brand.ftl

@@ -0,0 +1,21 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Thunderbird Brand
+##
+## Thunderbird must be treated as a brand, and kept in English.
+## It cannot be:
+## - Transliterated.
+## - Translated.
+##
+## Reference: https://www.mozilla.org/styleguide/communications/translation/
+
+-brand-shorter-name = Thunderbird بيتا
+-brand-short-name = Thunderbird بيتا
+-brand-full-name = Mozilla Thunderbird بيتا
+# This brand name can be used in messages where the product name needs to
+# remain unchanged across different versions (Daily, Beta, etc.).
+-brand-product-name = Thunderbird
+-vendor-short-name = Mozilla

ar/mail/branding/tb_beta/brand.properties

@@ -0,0 +1,7 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+brandShortName=Thunderbird بيتا
+brandShorterName=Thunderbird بيتا
+brandFullName=Mozilla Thunderbird بيتا
+vendorShortName=Mozilla