Fix initialization checks in Mat classes to handle '0' values

[emilneander]

Fix for Mat Initialization with CvType Constants

Problem:

When using certain CvType constant with a value of 0 (CvType.CV_8U), the Mat class was not initializing correctly due to truthy/falsy checks in the constructor.

Solution:

Explicitly check for undefined values in the Mat class constructor to ensure that values like 0 are treated as valid.

Changes:

• Updated checks in the Mat class constructor to explicitly check for undefined.
• Ensured that all other related classes handle 0 values correctly.

Example:

The issue was evident when using the CvType constants:

export const CvType = {
    "CV_8U" : 0,
    // ... other constants ...
};