Remove docname
Summary
Remove DocName from applications:
- Remove data member from 
WrapperApplicationclass, remove getters/setters from C++ and python APIs. - Remove 
SetDocNamefrom all applications - Show only 
Namein documentation - Remove column from GUI application browser
 - Fix python API 
Application.__str__() 
Rationale
For 95% of OTB applications, the extra doc name is useless. Except for maybe those three applications:
LSMSSegmentation                        Exact Large-Scale Mean-Shift segmentation, step 2
LSMSSmallRegionsMerging                 Exact Large-Scale Mean-Shift segmentation, step 3 (optional)
LSMSVectorization                       Exact Large-Scale Mean-Shift segmentation, step 4
the DocNames are same as the normal Names, but with spaces, casing and word order changed. The DocName adds nothing to the normal Name. Additionally it can be confusing for users when mixing cli/gui interfaces and reading documentation.
For simplification I propose to remove it, but we could also add a dummy implementation of GetDocName/SetDocName that does nothing, to improve backwards compatibility with < 7.x.
Closes #1789 (closed).
Copyright
The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.
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
 - Optionally, run 
git diff develop... -U0 --no-color | clang-format-diff.py -p1 -ion latest changes and commit