IO Balance function

[MohamedhBadr]

A function that checks the MRIO balance by:

1- Making sure that the matrix dimensions are compatible
2- Checks if total inputs = total outputs
3- Checks sector/product balance (sector/product inputs = sector/product outputs)

[konstantinstadler]

some comment in the iobalance.py
please also remove all .history files

[MohamedhBadr]

Added new commits, fixed issues with the IO balance function.

[konstantinstadler]

• change exception to ValueError as much as possible
• move to io_math
• signature: def is_balanced(Z, Y, VA, ... , a_tol, r_tol (as in numpy), report=False)
• report, if False, just return True/False, if report == True, return df

report df (think about return type, perhaps dict?)
checked_parameter, balanced
Z-VA = Z-FD, true/false

once this is done, go to mrio_system - IOSystem and add
def is_balanced(self, VA, a_tol, r_tol, report) (all except the one available in self)
io_math.is_balanced(Z=self.Z, VA=VA, ...)

write pytest function as well