* Add previous, current and next forms to form handler
* Add current, previous and next sales forms to form handler
* Implement current_lettings_form, current_sales_form and store year and form type in form
* refactor lettings_forms
* Use current, previous and next forms in lettings log model
* Use current, previous and next forms in sales log model
* use current, previous and next forms in csv service
* Remove "startyear_endyear" forms from form handler
* Remove name from form initializer and add an optional start year
* refactor get_form
* update csv test, fix form initialize
* rebase fix
* Refactor form_name_from_start_year method out
* remove unused variable
* fix typo, add date tests
* rebase, fix tests
* add comment to before test block
* Change the FormHandler back to only contain the form objects
* extract name
kosiakkatrina
ac4ee2a1fb