This update improves how double holiday pay recovery is calculated in the Belgian payroll system to ensure compliance with legal requirements. The change affects how employees' double holiday compensation is computed, ensuring accurate and legally compliant payroll processing for Belgian operations.

This will fix the computation of the double holiday pay recovery to match legal requirements.

Task: 3893867

This update removes unnecessary duplicate requests to Google Calendar when synchronizing appointments. The system now reuses information returned from Google during the initial sync instead of making additional requests, resulting in faster synchronization and reduced API calls. Google Meet URLs continue to be added to appointments correctly with this more efficient approach.

This commit removes the write override of calendar.event records, since this override
was doing unnecessary requests on Google side when synchronizing again events that were
just synchronized.

After this commit, the function get_post_sync_values() will reuse the values returned by
the insertion in Google and write in the event right away, saving requests to Google. The
objective of the previous write override was to write the google meet URL in the event,
and now this is still being done correctly by means of the new strategy.

related-to: https://github.com/odoo/odoo/pull/163364
task-389382

The quiz feature in website slides now uses green to highlight correct answers instead of purple, making it much easier for learners to quickly distinguish between correct and incorrect responses. This improves the user experience by providing clearer visual feedback during quiz interactions.

Currently, if we select the correct answer for a quiz question, `primary theme color(purple)` is applied to the `fa-check` icon. 
Hence, it is difficult to distinguish between the correct and incorrect answers.

This PR changes the color applied to the `fa-check` icon in case a correct answer is selected, from `primary theme color(purple)` to `success theme color(green)`.

Task-[3884674](https://www.odoo.com/web#id=3884674&menu_id=4722&cids=2&action=333&active_id=965&model=project.task&view_type=form)

This update improves how Google Calendar events are created and synchronized. When events are added to Google Calendar, the system now captures and saves important information (like meeting URLs) immediately after creation, rather than discarding it. This reduces the need for additional updates later and makes the synchronization process more efficient.

Before this commit, when inserting an event in Google side, we were throwing away the insertion values returned by Google and keeping only the event id. This was not a good practice because we could already write important values such as meeting URL and then spare future write calls. Additionaly, when writing values from google, we were sending through the context the 'write_dates' key, that would only be used once but would be kept in the context (when it is not needed).

After this commit, a callback function was added to write the event information right after the 'insert' function is executed, alongside of a function to get the desired post sync values describing which fields will be written in the event. Thus, we can write in the event right away after its creation. Since we are in a stable branch, this strategy was the only option to avoid changing the 'insert' function return and, by consequence possibly breaking custom code. In addition, now we delete the recently used 'write_dates' context key from the context in order to prevent future misuse of it.

task-3893827