Increase accuracy of Complex functions

[Prabhat1308]

⚙️ [OPTIMIZATION]

Description:
Some tests in Complex.t.sol have low accuracy (upto none or one decimal place). Improve the accuracy to at least 3 decimal places (for now, ideally should be around 7-8 decimal places).

Objective:
Optimise library and rewrite the following tests such that they have 3 decimal places of accuracy.

function testDivZ() public {}         // dont divide output by scale
function testCalcR() public {}        // dont divide output by scale
function testToPolar() public {}      // dont divide output by scale
function testPowZ() public {}         // have 3 decimals of accuracy instead of one

Source:

./test/Complex.t.sol