[mod] typification of SearXNG: add new result type File

This PR adds a new result type: File

    Python class: searx/result_types/file.py
    Jinja template: searx/templates/simple/result_templates/file.html
    CSS (less) client/simple/src/less/result_types/file.less

Class 'File' (singular) replaces template 'files.html' (plural).  The renaming
was carried out because there is only one file (singular) in a result. Not to be
confused with the category 'files' where in multiple results can exist.

As mentioned in issue [1], the class '.category-files' was removed from the CSS
and the stylesheet was adopted in result_types/file.less (there based on the
templates and no longer based on the category).

[1] https://github.com/searxng/searxng/issues/5198

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

docs/dev/result_types/main/file.rst

@@ -0,0 +1,7 @@
+.. _result_types.file:
+
+============
+File Results
+============
+
+.. automodule:: searx.result_types.file

docs/dev/result_types/main_result.rst

@@ -17,6 +17,7 @@ following types have been implemented so far ..
    main/keyvalue
    main/code
    main/paper
+   main/file
 
 The :ref:`LegacyResult <LegacyResult>` is used internally for the results that
 have not yet been typed.  The templates can be used as orientation until the
@@ -28,5 +29,4 @@ final typing is complete.
 - :ref:`template torrent`
 - :ref:`template map`
 - :ref:`template packages`
-- :ref:`template files`
 - :ref:`template products`

docs/dev/templates.rst

@@ -60,7 +60,7 @@ Fields used in the template :origin:`macro result_sub_header
 publishedDate : :py:obj:`datetime.datetime`
   The date on which the object was published.
 
-length: :py:obj:`time.struct_time`
+length: :py:obj:`datetime.timedelta`
   Playing duration in seconds.
 
 views: :py:class:`str`
@@ -469,38 +469,6 @@ links : :py:class:`dict`
   Additional links in the form of ``{'link_name': 'http://example.com'}``
 
 
-.. _template files:
-
-``files.html``
---------------
-
-Displays result fields from:
-
-- :ref:`macro result_header` and
-- :ref:`macro result_sub_header`
-
-Additional fields used in the :origin:`code.html
-<searx/templates/simple/result_templates/files.html>`:
-
-filename, size, time: :py:class:`str`
-  Filename, Filesize and Date of the file.
-
-mtype : ``audio`` | ``video`` | :py:class:`str`
-  Mimetype type of the file.
-
-subtype : :py:class:`str`
-  Mimetype / subtype of the file.
-
-abstract : :py:class:`str`
-  Abstract of the file.
-
-author : :py:class:`str`
-  Name of the author of the file
-
-embedded : :py:class:`str`
-  URL of an embedded media type (``audio`` or ``video``) / is collapsible.
-
-
 .. _template products:
 
 ``products.html``