[Refactoring] Split bounding_box struct

[niley7464]

This patch splites properties so that bounding_box struct does not have properties for all cases.
Also some functions like bb_setOptions, bb_decode have too many if cases, so I replaced it to use pure virtual functions.

Self evaluation:

1. Build test: [*]Passed [ ]Failed [ ]Skipped
2. Run test: [*]Passed [ ]Failed [ ]Skipped

[myungjoo]

You do not need to declare subclasses in the header.
As long as we now can have separated subclasses, I recommend making separated files for subclasses and remove all info about each subclass in the header. (e.g., /ext/nnstreamer/tensor_decoder/boxproperties/mobilenetssd.cc)

Then, you can apply factory method in this base class that creates sub classes according to the property name. By properly designing this, you will not need the enums for each "subclass", too. You will need to think about how to accept "new" subclasses from the base class.

[myungjoo]

The principle is to put commonly referenced classes and definitions in header.

If a class, #define, or a function is to be referenced by a single entity (e.g., by mobile-SSD only), you don't need to put it in a header.

[niley7464]

Moved subclasses to boxproperties subdir.
Thank you :)

[myungjoo]

For macos CI fail, rebase it to main.

For static checkers fail, please take care of doxygen entries.

[myungjoo]

This creates dependency from the base class to its derived classes.
It should be able to add new "subclass" without changing the base class (this!).

You may let the derived classes register required data and function callbacks for this switch-case statements.

e.g.,

class derived_class : public boxproperty
{
  friend class registerer;
  class registerer {
    registerer() { /* register a function callback doing "return new derived_class();" */ }
  };

  static registerer register;
};

in the derived .cc file.

Or you may find another mechanism to let tensordec-boundingbox.cc not be modified for new box-properties. (OCP!!)

[niley7464]

I misunderstood the previous comment because it was an unfamiliar concept.
Now base class do not need to be modifed when new derived class added or changed.

[myungjoo]

With the previous comment satisfied (OCP), you should be able to kick all these derived classes out of this header.

[niley7464]

Moved derived class to subdir!

[myungjoo]

LGTM.

We still have points that break OCP, yet, but we can now proceed and fix further later.
(you can find such points by trying (mimicking) to implement another boxproperty subclass. if you need to touch tensordec-boundingbox.h/cc (you actually need at this point), it means you have more to refactor.

However, further refactoring can be in another PR later.

[jaeyun-jung]

@niley7464 Next PR, I suggest using util function gst_tensors_info_get_nth_info() to get nth tensor-info ptr when iterating struct w/num_tensors. (config->info.info[nth]).

[myungjoo]

Let's move on and do the rest of refactoring in another PR.