Couple of links that need to update

[asadiqbal08]

reference to #112

From the menu in MFE in MITx Online edX, there are a couple links that need to be updated. (Sample page)

• "Dashboard" menu item should link to: MARKETING_SITE_URL/dashboard rather than LMS_BASE_URL/dashboard/
• "Profile" menu item should link to: MARKETING_SITE/profile rather than LMS_BASE_URL/u/USERNAME
  
  I added these to the frontend-component-header-edx MFE changes section in the description above.

Also, in the menu in the 'legacy' theme, clicking on the username will take you to LMS_BASE_URL/dashboard, but should take you to MARKETING_SITE/dashboard. (Sample page)

I added this to the mitxonline-theme changes section above (feel free to move it if it's the wrong section)

Acceptance Criteria:

• Update the corresponding env files to reflect the changes.
• Test it