[feat] categories: add icons for remaining category tabs (#6759)

Icons are provided for the main categories known to us.

The distinction between CATEGORY_GROUPS and CATEGORY_NAMES is abandoned in favor
of the latter.

HINT: we need single-color icons; transparent background and the color must be
`currentColor` so that the icons can be used in light/dark themes.

The following SVGs from the ionicons had to be revised (use ``currentColor``).

- client/simple/src/svg/ionicons/logo-rss.svg
- client/simple/src/svg/ionicons/radio-outline.svg
- client/simple/src/svg/ionicons/color-palette-outline.svg

For the following categories, I did not find any usable icons in Ionicons; new
SVGs were created for these categories.

- onions: client/simple/src/svg/ionicons/tor-browser.svg
- lyrics: client/simple/src/svg/ionicons/song-lyric-music.svg [1]
- packages: client/simple/src/svg/ionicons/package_2.svg [1]

[1] Based on Google's Material icons: https://fonts.google.com/icons

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/searxng.msg

@@ -11,7 +11,6 @@ from searx.weather import WeatherConditionType
 __all__ = [
     'CONSTANT_NAMES',
     'CATEGORY_NAMES',
-    'CATEGORY_GROUPS',
     'STYLE_NAMES',
     'BRAND_CUSTOM_LINKS',
     'WEATHER_TERMS',
@@ -26,33 +25,34 @@ CONSTANT_NAMES = {
 }
 
 CATEGORY_NAMES = {
-    'FILES': 'files',
-    'GENERAL': 'general',
-    'MUSIC': 'music',
-    'SOCIAL_MEDIA': 'social media',
-    'IMAGES': 'images',
-    'STOCK_IMAGES': 'stock images',
-    'VIDEOS': 'videos',
-    'RADIO': 'radio',
-    'TV': 'tv',
-    'IT': 'it',
-    'NEWS': 'news',
-    'MAP': 'map',
-    'ONIONS': 'onions',
-    'SCIENCE': 'science',
-}
-
-CATEGORY_GROUPS = {
-    # non-tab categories
-    'APPS': 'apps',
-    'DICTIONARIES': 'dictionaries',
-    'LYRICS': 'lyrics',
-    'PACKAGES': 'packages',
-    'Q_A': 'q&a',
-    'REPOS': 'repos',
-    'SOFTWARE_WIKIS': 'software wikis',
-    'WEB': 'web',
-    'SCIENTIFIC PUBLICATIONS': 'scientific publications',
+    "APPS": "apps",
+    "BLOGS": "blogs",
+    "DICTIONARIES": "dictionaries",
+    "FILES": "files",
+    "GENERAL": "general",
+    "ICONS": "icons",
+    "IMAGES": "images",
+    "IT": "it",
+    "LYRICS": "lyrics",
+    "MAP": "map",
+    "MOVIES": "movies",
+    "MUSIC": "music",
+    "NEWS": "news",
+    "ONIONS": "onions",
+    "PACKAGES": "packages",
+    "Q_A": "q&a",
+    "RADIO": "radio",
+    "REPOS": "repos",
+    "SCIENCE": "science",
+    "SCIENTIFIC PUBLICATIONS": "scientific publications",
+    "SOCIAL_MEDIA": "social media",
+    "SOFTWARE_WIKIS": "software wikis",
+    "STOCK_IMAGES": "stock images",
+    "TRANSLATE": "translate",
+    "TV": "tv",
+    "VIDEOS": "videos",
+    "WEATHER": "weather",
+    "WEB": "web",
 }
 
 STYLE_NAMES = {