Enhancement: WebOffice Templates

We are now able to use templates for WebOffice and use them as a starting point for new documents.

We are supporting the following mime types:

## OnlyOffice

- **MimeType:** `application/vnd.ms-word.template.macroenabled.12`
  **TargetExtension:** `docx`

- **MimeType:** `application/vnd.oasis.opendocument.text-template`
  **TargetExtension:** `docx`

- **MimeType:** `application/vnd.openxmlformats-officedocument.wordprocessingml.template`
  **TargetExtension:** `docx`

- **MimeType:** `application/vnd.oasis.opendocument.spreadsheet-template`
  **TargetExtension:** `xlsx`

- **MimeType:** `application/vnd.ms-excel.template.macroenabled.12`
  **TargetExtension:** `xlsx`

- **MimeType:** `application/vnd.openxmlformats-officedocument.spreadsheetml.template`
  **TargetExtension:** `xlsx`

- **MimeType:** `application/vnd.oasis.opendocument.presentation-template`
  **TargetExtension:** `pptx`

- **MimeType:** `application/vnd.ms-powerpoint.template.macroenabled.12`
  **TargetExtension:** `pptx`

- **MimeType:** `application/vnd.openxmlformats-officedocument.presentationml.template`
  **TargetExtension:** `pptx`

## Collabora

- **MimeType:** `application/vnd.oasis.opendocument.spreadsheet-template`
  **TargetExtension:** `ods`

- **MimeType:** `application/vnd.oasis.opendocument.text-template`
  **TargetExtension:** `odt`

- **MimeType:** `application/vnd.oasis.opendocument.presentation-template`
  **TargetExtension:** `odp`

https://github.com/owncloud/ocis/pull/10276
https://github.com/owncloud/ocis/issues/9785
