Fix task blocking

[h2zero]

Instead of incrementing the notificatin value via xTaskNotifyGive this will now set a specific bit in the task notification value which will be tested before blocking a task. This will prevent a task from blocking indefinitely if the event that calls taskRelease occurs before entering the blocked state.

• Adds a config setting for the bit to set in the task notification value.

Refactor NimBLEClient::connect and NimBLEClient::secureConnection.

This change ensures that only the function that sets m_pTaskData clears it, potentially preventing a segmentation fault.

• Client will no longer disconnect if task timeout occurs when waiting for MTU exchange response.

Fixes #222