cache the next, current and previous results in a separate task

Change get_safe_search_level logic back

change: renamed get_safesearch_level variables

refactor: changed Cookie to use Cow to facilitate using references when building

change: revert Cookie Strings back to &str

fix: safe search url parameter ignored

refactor: moved settings parsing out of results

modify: changed cache_key format data

Moved parsing of cookie_value, config to cache_key

Merge branch 'rolling' into FIX/463_results_from_different_search_engines_get_cached_as_the_same_key

fix: add comma separator and format macro

:recycle: refactor: standardize the `content-type` header by using an enum value over typing it manually (#474)

fix: changed dereferencing

fix: added a config parse backup

fix: modify cache key with engines used for search

Merge branch 'rolling' into CHORE/461_display-the-user-provided-settings-from-the-config-or-the-ui-in-the-settings-page

♻️ refactor: start tracking page numbers from 0 instead of 1 in the backend (#467)

🚨 chore: make cargo format checks happy (#461)

Merge branch 'rolling' into CHORE/461_display-the-user-provided-settings-from-the-config-or-the-ui-in-the-settings-page

🚸 chore: pass the `safe_search_level` & `upstream_search_engines` as a hashmap in the `settings` view function (#461)

🐛 fix: explicit `content-type` header for the search page response (#458)

🐛 fix: explicit Content-Type header for HTTP response (#457)

✨ feat: pass the new animation config option (#424)

:recycle: Refactor cache system (#399)

:recycle: Clean some code, fix bug (#396)

🔥 chore: remove the debug macro from the code (#302)

🚨 chore: make cargo clippy linter happy (#302)

♻️ refactor(routes): serve the new maud file for search page and remove unwanted functions and pass values to the maud html template directly (#302)

♻️ refactor(routes): serve new the maud files instead of handlebars files (#302)

Create separate search_result_parser

🧹 chore: make github actions happy (#227)

Merge branch 'rolling' into feat-inform-user-when-no-engines-are-selected

✨ feat: add code to handle aggregation when no engines are selected (#227)

✨ feat: implement code to fetch results based on parameters, cookies & config (#210)

🛠️ fix: improve the documentation & move code in the correct files (#244)

Remove unnecessary clones

Instead of caching jsons, we can cache the original structure

Cache refactor - add an in-memory cache, so redis is not needed

Merge branch 'rolling' into reorganize-code-and-restructure-the-codebase

🧹 chore: make github actions happy (#205)

🧹 chore: make github actions happy (#205)

Merge branch 'rolling' into change-document-style-with-linter-warnings

🧹 chore: make clippy happy (#201)

Merge branch 'rolling' into feat-disallow-user-to-search-via-lists

Merge branch 'rolling' into optimize-and-make-code-idiomatic

Merge branch 'rolling' into optimize-and-make-code-idiomatic-3

⚙️ refactor: reorganize code & restructure codebase for better maintainability (#207)

⚙️ refactor: change & add documentation to the code based on the lints (#205)

✨ feat: implement new search parameter `safe_search` & code to disallow

🧹 chore: add fixes to code & make rustfmt & clippy happy (#180)(#178)