[New tool] SSL Certificate Format Conversion Tool

[zeng202211]

Clear and concise description of the feature you are proposing

Input Formats: PKCS#12, DER, and PEM.

Output Formats: PEM and DER

Is their example of this tool in the wild?

https://www.lddgo.net/encrypt/cert-format-converter

Additional context

No response

Validations

• Check the feature is not already implemented in the project.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• Check that the feature can be implemented in a client side only app (IT-Tools is client side only, no server).

[sharevb]

Hi @zeng202211 and @CorentinTh , implemented in #1306