iOS SDK 2.7.0

The way Templates are handled is changing, and therefore this is a minor release. None of the changes are breaking, but if you are manually integrating the SDK, the various templates are now in their own files.

Bugfixes:

[LP-11143] fix accessibility elements (#343)
[LP-11154] Fixing action not triggered (#341)
[LP-11206] Adding synchronization (#348)
[LP-11199] Fixing background deadlock (#350)
Synchronize access to callbacks (#347)
[LP-11199] Fixing a crash when entering background
[LP-11142] Fixing a potential objc_release crash (#337)