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

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>

This patch adds a new result type: Paper

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

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

This patch adds a new result type: Code

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

Signed-of-by: Markus Heiser <markus.heiser@darmarIT.de>

This patch adds GitHub Code Search [1] engine to allow querying the codebases.

Template code.html is changed to allow passthrough of strip and highlighting
options.

Engine Searchcode is adjusted to pass filename and not rely on hardcoded
extensions.

GitHub search code API does not return the exact code line indices, this
implementation assigns the code arbitrary numbers starting from 1
(effectively relabeling the code).

The API allows for unauth calls, and the default engine settings default to
that, although the calls are heavily rate limited.

The 'text' lexer is the default pygments lexer when parsing fails.

[1] https://docs.github.com/en/rest/search/search?apiVersion=2022-11-28#search-code

Co-authored-by: Markus Heiser <markus.heiser@darmarIT.de>

Everyone should have already switched from legacy methods

The engines now all use KeyValue results and return the results in a
EngineResults object.

The sqlite engine can return MainResult results in addition to KeyValue
results (based on engine's config in settings.yml),

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

This patch adds a new result type: KeyValue

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

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

BTW: Rename the manufacturer-specific name ``ion-icon`` of the icon set in
SerXNG to ``sxng-icon-set`` --> The icon set can be assembled together as
desired in the FE and should therefore not have a manufacturer-specific name in
the style and template definitions.

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

This patch implements the template generation of the template:

  searx/templates/simple/icons.html

by the way the icon set (the icon names) has been normalized:

  film-outline   --> film
  magnet-outline --> magnet
  ..
  warning        --> alert

Some missing (categorie) icons had been added.

Some of the ionicons are not suitable for a dark theme, we fixed the svg
manually in src/svg/ionicons:

- https://github.com/searxng/searxng/pull/4284#issuecomment-2680550342

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