Deprecate mapnik in 7.0

Summary

This MR improves the handling of deprecated features, and also deprecate Mapnik related modules.

Rationale

See #1692 (closed).

Implementation Details

CMake build system

• Improvements on the handling of deprecated modules. It is now possible to declare a whole module DEPRECATED.
• If the option OTB_USE_DEPRECATED=OFF, this module will be disabled.
• The modules export macros are now consistent (uppercase/lowercase). For instance OTBIOTileMapExport.h defines:
  • OTBIOTileMap_EXPORT
  • OTBIOTileMap_DEPRECATED
  • OTBIOTileMap_DEPRECATED_EXPORT

Classes and files

• The Mapnik modules OTBMapnik and OTBVectorDataRendering are now deprecated

Documentation

Doxygen tags \deprecated have been added.

Additional notes

Copyright

The copyright owner is COPYRIGHT OWNER (OR OWNER'S AGENT) and has signed the ORFEO ToolBox Contributor License Agreement.

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Check before merging:

• All discussions are resolved
• At least 2 votes from core developers, no vote.
• The feature branch is (reasonably) up-to-date with the base branch
• Dashboard is green
• Copyright owner has signed the ORFEO ToolBox Contributor License Agreement