Draft: Add Join Tables Filter

The Join Tables Filter is a filter that operates on two Table objects to perform an SQL-style Join operation. It outputs one Table object. The goal is to combine the rows of both tables into one bigger table based on a related "key column" between them. The two input tables are referred to as left and right. In each input table, the values in the key column act like unique IDs for their respective rows. During the merge, the attributes of each item will be given with respect to its ID. Below is an example of a basic join operation :

First input Table (left)

Name	Age	Sex
Alex	25	M
Beth	41	F
Cory	33	M

Second input Table (right)

Name	Height(cm)	Weight (kg)
Cory	184	88
Alex	175	74
Beth	168	70

Result of a Join operation performed with LeftKey = "Name"and RightKey = "Name" :

Name	Age	Sex	Height(cm)	Weight (kg)
Alex	25	M	175	74
Beth	41	F	168	70
Cory	33	M	184	88

This Filter exposes the following parameters :

• Join Mode {intersection, union, left, right} : specifies which Join method to perform. This is useful when the key columns do not share exactly the same values. left keeps the keys of the left input table, right keeps the keys of the right input table, intersection keeps only the keys that are present in both tables, union keeps the keys from both tables.
• Left Key (array list combo box) : Column name of the left table to treat as key
• Right Key (array list combo box) : Column name of the right table to treat as key