Tasks backend + frontend

[stepan662]

BE

• [ ] add tasks endpoints - create task, edit task, add/remove keys
• [ ] endpoint for counting untranslated/unreviewed keys
• [ ] endpoint for generating report

FE

• [ ] add task create/edit form
• [ ] tasks overview
• [ ] user's tasks
• [ ] batch operations

[stepan662]

Consider also counting of words (there might be some settings) https://github.com/tolgee/tolgee-platform/issues/2348

[stepan662]

https://www.figma.com/design/wVmz098ZrSxswOI0nbIjQ2/Design-system-Tolgee?node-id=1718-54457