Keep task id in url in entity task lists (+ fixes and updated japanese translation)

[frankrousseau]

Problem

It's hard to navigate back from a task to an entity task list.

Solution

• Store the selected task ID in the URL query.
• On the mount of the assets/shots/sequences/episodes/edits lists, select the given task ID.
• Add a back button to the task page.

+ Some dark theme fixes + Update Japanese translation