Resolve "Add metadata to the output files"

Closes #171

See merge request !125

Resolve "Bump docker version for IA support applications"

Closes #179

See merge request !124

Resolve "Handle end of support of Python 3.8"

Closes #158

See merge request !123

From now on, S1Tiling may or may not work on Python 3.8.

We permit using new features from Python 3.9, yet we operate no change yet to
replace current code with new simplified constructs from Python 3.9.

Resolve "Generate Incidence Angle maps"

Closes #161

See merge request !119

And extent the scenatio documentation

and improve related cross-references

…pipeline upstream OTB app has no input image

`process_one_tile` now takes a list of optional context managers.

All DEM related information have been moved to `DEMWorkspaceConfiguration`
context manager.

And improve their respective documentations (© notices, version number…)