fix(FEC-11708): V3 - cast on multiple players - if try to cast when other player are casting, the player will be disabled

[SivanA-Kaltura]

Description of the Changes

We set isCastInitiator=true on cast button click, and set it to false if the cast request didn't succeed or the cast menu lost focus.

However, if player A is already casting, when we click on the button in player B, we set isCastInitiator=true but we have no event to indicate that the cast request did not succeed, since a cast request can't be made at all while player A is casting, and so for player B isCastinitiator is not set to false.

When having 3+ players this can cause a situation where multiple players will have isCastInitiator set to true when a player starts casting, which will cause them all to connect to the same remote session.

To prevent this, we need to reset isCastInitiator for ALL players on disconnect.

Fixes FEC-11708.
Related PR: kaltura/playkit-js-ui@0470ffa

CheckLists

• changes have been done against master branch, and PR does not conflict
• new unit / functional tests have been added (whenever applicable)
• test are passing in local environment
• Travis tests are passing (or test results are not worse than on master branch :))
• Docs have been updated