[10PT] - Implement validations

[Nemwel-Boniface]

In this milestone, I will implement validations for the data to be entered and stored in the project to reduce garbage data being stored in the project. The main types of validations to be implemented include:

• ensure presence is true

• ensure numericality is true where applicable

• ensure the length of data entered is correct

• type of data entered is correct using regular expressions

• AOB

This is work in progress and should not be moved to the "done" until the project is done.