Fix a bug of synctex edit command

[naoh16]

This PR would be a solution for the following issues:

• Scroll editor to page is not working but scroll pdf to cursor works fine. #186
• GET 500 while use synctex to scroll editor to page #200

Their problem are occured when the notebook_dir is a blank, because the generated path is an absolute path from the root: e.g. '/sample.tex'.

NOTE: This is a same solution of the implementation in build_synctex_view_cmd() function.

jupyterlab-latex/jupyterlab_latex/synctex.py

Lines 108 to 118 in 77beeb8

	pdf_path = os.path.join(self.notebook_dir, tex_name+".pdf")
	tex_path = os.path.join(self.notebook_dir, tex_name+".tex")
	cmd = (
	c.synctex_command,
	'view',
	'-i',
	f'{pos["line"]}:{pos["column"]}:{tex_path}',
	'-o',
	f'{pdf_path}'
	)

[github-actions]

👈 Launch a Binder on branch naoh16/jupyterlab-latex/fix_synctex

[ktaletsk]

Looks good! Thank you @naoh16