Add Font Awesome 5 icons.

[IlyaKisil]

This PR adds latex commands for FontAwesome5 free icons. Address issue #206.

Obviously, there is not need to use these new icons associated with the well known frameworks all the time. However, it could add a nice touch to your CV. Here is just an example of how some new icons look like:

This PR is not based on official fontawesome5 package for LaTeX. Instead, it defines commands based on icons.json metadata and *.otf files for fonts which are available as a part of Font Awesome for Desktop. It also provides a script used to generate these definitions, which could be used for future releases of Font Awesome. This is analogues to the way current fontawesome.sty has been generated with the use of scripts from latex-fontawesome project.

Steps in order to use icons from so-generated fontawesome5.sty file:

1. Use search on the official website to find icon by name or related tags.

2. Use unicode of the desired icon to search for latex definition in fontawesome5.sty.

3. Copy and paste the associated definition in your latex document.

[IlyaKisil]

fontawesome5.sty does not depend on fontawesome.sty, therefore, the latter can be easily removed. At the moment, If some the same latex command is defined in both, them the one from fontawesome5.sty is used.

I haven't checked whether all icons that are currently used in awesome-sv.cls are present in fontawesome5.sty. However, if some are icons (not commands) are missing then there should be something similar

[OJFord]

Thank you - I think many of us have made this or similar fixes over the years as posquit0's had other priorities. I have push access now to help maintain Awesome-CV; so I went with my old PR for this (#235/#344) for no reason other than my own familiarity, that I know it's been working for me.

Please do ping me/open another PR if something's still not right or I missed something though! Cheers.