fix(views): use correct grammar for interval name and period

[igorsimb]

Fixes #98 Fixes #115 This also eliminates the need the for min="2" workaround of scrape_interval_form.interval_value introduced in https://github.com/igorsimb/mp-monitor/pull/116

Summary by CodeRabbit

• New Features

  • Added a function to translate the intervals of periodic tasks into Russian, enhancing support for Russian users.

• Bug Fixes

  • Updated the minimum value for interval_value in interval creation forms from "2" to "1", allowing more flexibility in setting intervals.
  • Improved error handling in interval creation to provide better feedback when no time unit is selected.

• Refactor

  • Changed the display method in the update interval form to show scrape_interval_task directly, improving clarity in schedule representation.
  • Updated the order of migration dependencies to ensure correct sequence during database setup.

• Documentation

  • Removed the ItemSchedule model from the database schema, simplifying the structure.

• Tests

  • Added new test cases to verify the Russian translation functionality of intervals.