Add initial version of dark mode support

[kgrosvenor]

This commit uses the key STRAPI_THEME from localStorage to determine the users interface mode colors, if this doesn't exist it falls back onto browser settings

[melishev]

@kgrosvenor - It's cool, I read it and I liked it, but there is one problem:

Description of the media file - remains unchanged

[kgrosvenor]

Yeah i see, thanks @melishev . i will check this out next time im free 👍

So specifically the table arrows need styling and also the media captions need looking at

[SalahAdDin]

Yeah I see, thanks @melishev . I will check this out next time I'm free 👍

So specifically the table arrows need styling and also the media captions need looking at

@kgrosvenor, did you check it?

[melishev]

@kgrosvenor so what?

[SalahAdDin]

@kgrosvenor how could i help you?

[kgrosvenor]

Hey @melishev , taking a look at the issues now and setting up the dev environment, @SalahAdDin what would you suggest?

[kgrosvenor]

@melishev , @SalahAdDin Media captions and table column buttons have been taken care of, kindly review and test 💯