Fixes and pull requests

Updates:
Added etl::type_list_has_duplicates_of and etl::type_list_count_of

Fixes:
#1186 Fix usage of noexcept
#1203 Potential issue with forwarding in etl::delegate
Improved forwarding of arguments to bound functions.
Added compile time checks for functors and lambdas argument compatibility.

Pull Requests:
#1012 Implement Signal
A signal/slot implementation.
#1155 Added callbacks when a timer is inserted or removed
#1175 Debug assert
Added ETL_DEBUG_ASSERT macro, which is a debug only assert.
Added extra assert enable/disable macros.
#1188 etl::array checks
#1190 Enforce semicolon after ETL_ASSERT
#1191 Introduce cast to void for condition of assert
Avoids compiler warnings for unused results of ETL_ASSERT and ETL_DEBUG_ASSERT
#1192 Allow easy creation of generic exceptions with just a text
#1195 Added conditional support of noexcept to fix IAR support
#1196 Added back in support for populating non 8 bit strings with 8 bit data
#1198 Add etl::is_constant_evaluated
#1199 Added support for transitions on state enter for HFSM
#1201 etl::span checks