Export Juvix source code to latex

[janmasrovira]

This pr adds two new commands related to latex.

1. juvix dev latex getJuvixSty. This command prints the contents of the juvix.sty latex package to stdout. It has no options and the expected usage is juvix dev latex getJuvixSty > juvix.sty.
2. juvix dev latex export. Expects a .juvix file as an argument and outputs to stdout the highlighted module in latex format. Optional flags --from LINE, --to LINE to output only the specified line range. There is a --mode flag to choose how you want the output.

   • standalone: Output a ready to compile LaTeX file
   • wrap: Wrap the code in a Verbatim environment
   • raw: Output only the code (default: standalone)
   

3. As shown in the standalone output, one is allowed to choose the theme when importing the juvix package like this: \usepackage[theme = latte]{juvix}. Available themes are latte, frappe, macchiato, mocha.

Examples:
To generate the following output I ran these commands:

cd examples/milestones/HelloWorld
mkdir latex
juvix dev latex getJuvixSty > latex/juvix.sty
juvix dev latex export HelloWorld.juvix > latex/main.tex
cd latex
xelatex main.tex
open main.pdf

1. with \usepackage[theme = latte]{juvix}:
   
2. with \usepackage[theme = frappe]{juvix}:
   
3. with \usepackage[theme = macchiato]{juvix}:
   
4. with \usepackage[theme = mocha]{juvix}: