feat(UI): Add possibility to choose exercise display order

[hernoufM]

• Kind: enhancement

• Related to this PR on public corpus

Description

This PR provides users with the ability to sort exercises in the exercises index based on various criteria derived from metadata. The initial version relies solely on groups structured according to the exercise provider's preference, which we refer to as "By legacy". The list of newly added sorting options includes:

• By deps: This sorting does not divide exercises into specific subgroups. It uses an algorithm to determine dependencies between exercises based on the skills they train and require, as well as any connections between two exercises.
• By stars: This groups exercises based on their star ratings, from easiest to most difficult.

This PR is closely related to the upgrade of the public corpus, which adds a logical progression to follow and fresh new exercises for practicing OCaml programming language.

Regarding the specific code base changes, all callbacks triggered by clicking on one of the buttons (Exercises, Playground, Lessons, etc.) now have a common type called tab_handler. Previously, each of these callbacks generated the content of the main page without allowing the main page to be divided into multiple modes (in our case, these modes are exercise sorting modes). To address this, an optional argument ?clear_cache was added to prevent the page from always rendering in its initial state.

Co-authored-by: Dario Pinto (@RadioPotin)

[AltGr]

Closing as superseded by #564
@hernoufM I invite you to check out the improvements ;)