Draft: New Profiling module: the way to estimate individual nodes and the framework

The module itself is located in

dagflow/tools/profiling

and have a structure:

profiling.py - base Profiling class with methods for working with the table of results and printing them.

individual.py - IndividualProfiling - Profiling class for estimating the time of individual nodes.

framework.py - FrameworkProfiling - Profiling class that used to estimate the interaction time between nodes (framework time).

SleepyNode.py - A node that sleeps for a certain time (for debugging and testing).