Re-land "[lldb/docs] Silence warnings when generating website"

This patch re-lands f0731d5b with more fixes and improvements.

First, this patch removes `__eq__` implementations from classes that
didn't implemented `operator!=` on the C++ implementation.

This patch removes sphinx document generation for special members such
as `__len__`, since there is no straightforward way to skip class that
don't implement them. We also don't want to introduce a change in
behavior by implementing artifical special members for classes that are
missing them.

Finally, this patch improve the ergonomics of some classes by
implementing special members where it makes sense, i.e. `hex(SBFrame)`
is equivalent to `SBFrame.GetPC()`.

Differential Revision: https://reviews.llvm.org/D159017



Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>