Add i18n strings for chapter skip settings

Replace hardcoded Chinese text in PlayerSettingsModal with i18n keys.
Add HeaderChapterSkipSettings, LabelSkipChapterIntro,
LabelSkipChapterOutro, LabelSeconds to en-us and zh-cn strings.

client/strings/en-us.json

@@ -129,6 +129,7 @@
   "HeaderBackups": "Backups",
   "HeaderBulkChapterModal": "Add Multiple Chapters",
   "HeaderChangePassword": "Change Password",
+  "HeaderChapterSkipSettings": "Chapter Skip Settings",
   "HeaderChapters": "Chapters",
   "HeaderChooseAFolder": "Choose a Folder",
   "HeaderCollection": "Collection",
@@ -567,6 +568,7 @@
   "LabelSearchTitleOrASIN": "Search Title or ASIN",
   "LabelSeason": "Season",
   "LabelSeasonNumber": "Season #{0}",
+  "LabelSeconds": "seconds",
   "LabelSelectAll": "Select all",
   "LabelSelectAllEpisodes": "Select all episodes",
   "LabelSelectEpisodesShowing": "Select {0} episodes showing",
@@ -629,6 +631,8 @@
   "LabelShowSeconds": "Show seconds",
   "LabelShowSubtitles": "Show Subtitles",
   "LabelSize": "Size",
+  "LabelSkipChapterIntro": "Skip chapter intro",
+  "LabelSkipChapterOutro": "Skip chapter outro",
   "LabelSleepTimer": "Sleep timer",
   "LabelSlug": "Slug",
   "LabelSortAscending": "Ascending",

client/strings/zh-cn.json

@@ -129,6 +129,7 @@
   "HeaderBackups": "备份",
   "HeaderBulkChapterModal": "添加多个章节",
   "HeaderChangePassword": "更改密码",
+  "HeaderChapterSkipSettings": "章节跳过设置",
   "HeaderChapters": "章节",
   "HeaderChooseAFolder": "选择文件夹",
   "HeaderCollection": "收藏",
@@ -567,6 +568,7 @@
   "LabelSearchTitleOrASIN": "搜索标题或 ASIN",
   "LabelSeason": "季",
   "LabelSeasonNumber": "第 {0} 季",
+  "LabelSeconds": "秒",
   "LabelSelectAll": "全选",
   "LabelSelectAllEpisodes": "选择所有剧集",
   "LabelSelectEpisodesShowing": "选择正在播放的 {0} 剧集",
@@ -629,6 +631,8 @@
   "LabelShowSeconds": "显示秒数",
   "LabelShowSubtitles": "显示标题",
   "LabelSize": "文件大小",
+  "LabelSkipChapterIntro": "跳过章节开头",
+  "LabelSkipChapterOutro": "跳过章节结尾",
   "LabelSleepTimer": "睡眠定时",
   "LabelSlug": "Slug",
   "LabelSortAscending": "升序",