Improve bliss.shell package

Close #2089 (closed)

This MR move few things in order to provide a little more consistent shell/cli package.

• Move bliss.data.display into bliss.shell.data (as result bliss.shell.data is only for BLISS lib)
• Deflate bliss.shell.__init__ in order to not import the world (you could want to import shell helper without importing CLI objects)
• Pass session env as argument instead of using import __main__
• Create bliss.shell.formatters to share generic formatters (and rename FormatedTab -> IncrementalTable)