[DashTree] Changes to parsing values from "Role" tag

[CastagnaIT]

Description

Changes on "Role" tag value parsing:

Disabled "subtitle", "caption" uses

"subtitle" looks like a kind of old workaround to set content type,
but "should" be used only to signal burned-in subtitles to video stream (not CC 608 etc..)

"caption" instead has been used to set impaired flag, imo its not correct thing
its not a rule that "caption" stand for impaired, as you can read also
on wikipedia this should not be a rule, but only some countries may use it as rule

IOP/ISO EIC specs say that "subtitle" and "caption" have same meaning of burned-in subtitles
so lets try to remove both and we will see if someone complains

(compared to the past the current source code have more robust code to identify the “content type” so it should be low risk of breaking some service by removing "subtitle" case value)

Deprecated custom "forced" support

i have implemented "forced" value years ago, i was not aware of "forced-subtitle" official specs value,
so lets deprecate it, for future removal

Motivation and context

fix #1768

How has this been tested?

cant be test by my part

Screenshots (if appropriate):

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

Checklist:

• I have read the Contributing document
• My code follows the Code Guidelines of this project
• My change requires a change to the Wiki documentation
• I have updated the documentation accordingly

[CastagnaIT]

@matthuisman have you some custom uses of "Role" tag values?
in case let me know if this code change may result in any headaches

[matthuisman]

i think i can just add both forced and forced-subtitle to keep backwards compatbility?
And swap to alternate or commentary instead of caption

[matthuisman]

actually, i think im OK

I do have some code to work-around IA not supporting this already:

Thats all i do in regards to "Role"
In the above - i just set forced on the adaption set if i see forced-subtitle role

[CastagnaIT]

yes you are doing right things
then you dont need change nothing
for Kodi 22 if you want you can remove the setAttribute “forced” from Role since that case will be handled

PS. anyway "forced" attrib to AdaptationSet will be kept, is not the scope of this PR

[matthuisman]

my code is meant to be backwards compatible way back to Kodi 17 hehehe.
So ill just leave it - it wont hurt anything
itll just have 2x indicators for forced