botapi: support file uploads

Blockers:

• File uploads/multipart/form-data support in ogen
• Investigate file_unique_id generation.

TDLib file_unique_id generator implementation links:
https://github.com/tdlib/td/blob/3ff9723722a88022e4698a5562c2f8901dec63fa/td/telegram/files/FileManager.cpp#L739
https://github.com/tdlib/td/blob/3ff9723722a88022e4698a5562c2f8901dec63fa/td/telegram/files/FileLocation.h#L284
https://github.com/tdlib/td/blob/3ff9723722a88022e4698a5562c2f8901dec63fa/td/telegram/files/FileLocation.hpp#L326
https://github.com/tdlib/td/blob/3ff9723722a88022e4698a5562c2f8901dec63fa/td/telegram/files/FileLocation.h#L164
https://github.com/tdlib/td/blob/3ff9723722a88022e4698a5562c2f8901dec63fa/td/telegram/files/FileLocation.hpp#L174

[ernado]

Can we already add methods with file uploads to openapi schema?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.