Export process mode

https://redmine.teklia.com/issues/7497

Requires backend#1858 (closed)

• PROCESS_MODES in src/config.ts should be updated to add a display name for the export mode. This should make it visible in the process list's mode filter.
• The process configuration page should:
  • Allow viewing the configuration of an export process;
  • Forbid editing the configuration of an export process;
  • Forbid creating or applying templates on an export process.
• The process status page should enable the button leading to the configuration page for an export process.
• The rows in the process list page should allow accessing the process configuration page for an export process when it is not started.
• The process element filter page should not allow an export process.
• The process dataset selection page should not allow an export process.