Add support for binary operators (e.g. +, -, *, /) in formulas

The formula parser and compiler should be enhanced to include support for binary operator expressions, e.g. 5 * 2 or "Hello" + " " + "World".

We should support at least the following operators, with the ability add more if needed:

Operator	Description
`+`	Add two numbers or concatenate two strings.
`-`	Subtract a number from another.
`*`	Multiply two numbers together.
`/`	Divide a number by another.
`%`	Compute a number modulo another (remainder of integer division)
`&&`	Compute the logical AND of two variables¹.
`\\|\\|`	Computer the logical OR of two variables¹.

¹ - 0, "", null and false should be considered falsy for logical operations.

Nice to Have

Here are some optional ways to improve this feature:

Operators should respect widely accepted operator precedence rules (e.g. 5 + 10 * 2 is 5 + 20, not 15 * 2)
Support for parentheses could be added to allow more control over precedence.

If these optional features are not added, new issues should be created to deal with them in the future.