Plugins: fix google-analytics link

[retrofox]

Fix #4993

• Fix link in google-analytics link: '/plans/features/google-analytics/{siteSlug}'
• Fix back link in the header cake in the plans page
• Remove unused business-plugin.jsx file

Here description and testing.

cc @drw158 @dmsnell

[davewhitley]

Hm, the link works, but now the inactive plugin styles are broken (the lower opacity and gray color). I believe a is-disabled class was being added to .wpcom-plugins__premium-panel and wpcom-plugins__business-panel

#4995 (comment) For reference

[davewhitley]

Master also has the same problem though. I'm not sure what happened. wpcalypso looks fine though.

Shall I create a new issue for the disabled plugins problem?

[davewhitley]

Hah, actually, I was looking at a site that had the Business plan. Never mind!

[dmsnell]

Hah, actually, I was looking at a site that had the Business plan. Never mind!

I wondered if that might have been the case 😄

[dmsnell]

@retrofox

[retrofox]

thanks guys for the review