[build] Update `update_mbed_repo` target
[fix][build] Revision variable name
[fix][mbed] Add missing `common.h`
[fix][mbed] Remove stale assertions
[fix][mbed] Remove stale `send_all()`
[fix][mbed] Add missing declarations
[mbed] Provide default setting for `XI_IO_LAYER` -

user may override this in `xi_user_config.h`, but they must know
what they are doing then!
[fix][mbed] Delete stale reference to `conn`
[fix][mbed] Fix compilation error
[fix] Typo that producess very odd compiler errors
[fix] Very trivial copypasta
[refac][fix] makes the library to use less stack memory
[refac] removed static text references
[fix] added missing newline
[fix] uninitilized values through jump point
[fix] csv_layer_data_generator_datapoint safe initialization
[fix] added missing enable macro
[fix] fixed generator data initialization
[fix] csv_layer_data_generator_feed internal loop skip data initialization
[fix] warning related to comparition signed vs unsigned