mod_http_file_share: Fix name of max-file-size tag

mod_http_file_share: Expand registry to fix extra tag Error registry compact format doesn't support extra.tag so needs to be the more verbose format

mod_http_file_share: Verify final file size on completion of upload

mod_http_file_share: Add file type filter Unlike mod_http_upload, this can't be bypassed by uploading with a different file extension.

mod_http_file_share: Add file size limit (default 10M)

mod_http_file_share: Validate that filename does not contain '/'

mod_http_file_share: Return proper error if unauthorized

mod_http_file_share: Add basic access control Partly lifted from mod_external_services

mod_http_file_share: Add support for external file upload service PUT /upload/:slot/:filename Authorization: Bearer JWT{ uploader, filename, filesize, filetype, exp }

mod_http_file_share: Let's write another XEP-0363 implementation This variant is meant to improve upon mod_http_upload in some ways: * Handle files much of arbitrary size efficiently * Allow GET and PUT URLs to be different * Remember Content-Type sent by client * Avoid dependency on mod_http_files * Built-in way to delegate storage to another httpd