changed variables in ns_turn_session.h and to bool

[redraincatching]

changed variables that appeared in ns_turn_session.h and and their uses to bool to follow C11 idioms

approach was as follows:

• if a variable of type int was only being used as a boolean, replace it with bool as defined in <stdbool.h>
• replace its declaration and assignment with true/false, depending on prior assignment as 0/1
• then check any error that appear after build and update them to reflect changes

changes were only made when i was certain the variables were not being used as an int, so i may have missed some

[eakraly]

Hi @redraincatching
I suggest you split PRs - make one change at a time (one variable or one method). It would be much easier to review.

In this PR, you make changes to function definitions but do not change calls to the functions
For example, you change stun_is_command_message_full_check_str to accept bool but did not change calls to it. So what you have is silent casting and this may introduce some very subtle errors.

[ggarber]

@redraincatching Can you take a look at the comment?