Add implementation for TimeSpan.ToString()

[josesimoes]

Description

Add code to implement TimeSpan.ToString().

Motivation and Context

• Resolves Implement HAL_Time_TimeSpanToStringEx Home#122

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [] My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Signed-off-by: José Simões [email protected]

[nfbot]

Hi @josesimoes,

I'm nanoFramework bot.
Thank you for your contribution!

A human will be reviewing it shortly. 😉

[ghost]

Aren't the "SafePrintf***()" methods already existing with another name somewhere else ?

[josesimoes]

@MikroBusNet almost... they look the same but these Safe** use reference parameters instead.

[josesimoes]

@MikroBusNet I've look harder and you are correct: there are CLR_Safe**** but just not implemented.
I'm working on it now. Thank you very much for pointing this! 👍 💯