text: Title: Utilize {% querystring %} template tag
  Body: ### Describe the problem
  
  The querystring handling pagination currently has quite complex logic in `weblate.trans.forms.SearchForm`. Most likely it can be fully eliminated by using the  `{% querystring %}` template tag introduced in Django 5.1 (required by Weblate since https://github.com/WeblateOrg/weblate/pull/13636) see https://docs.djangoproject.com/en/5.1/releases/5.1/#querystring-template-tag.
  
  
  ### Describe the solution you would like
  
  I believe using `{% querystring %}` in the template can replace `items`, `urlencode` and `reset_offset` methods in the form.
  
  ### Describe alternatives you have considered
  
  _No response_
  
  ### Screenshots
  
  _No response_
  
  ### Additional context
  
  https://github.com/WeblateOrg/weblate/blob/b4c476f9ef7e38fd854169d270953abbee4c5d98/weblate/trans/forms.py#L809-L852