extended edit-record function to delete existing file if new file uploaded during update submission, and new tests for file deletion

replaced physical file with temp file in subtest 'Create document' in moongate & household tests, as already used in 'Edit file' subtest

changed content of 404 template to accomodate file not found as well as page not found; adjusted test messages accordingly

bugfix - chatgpt generated incorrect syntax - $dir is parent of $filepath, hence $dir subsumes/contains $filepath

moved download validator into App::Utils, added download validation to DPW

converted all 'edit' requests from POST to GET

extended moongate & dpw tests to test file update - with a lot of help from chatgpt

moved documents_path setting to config_local.yml files to allow site-specific configuration; Moongate documents_path now defined in config_local.yml (same way DPW docs_path is defined); new test file for household based on moongate.t, most dpw.t tests now skipped as they are not htmx-aware