Remove SPARKDEX and BRIDGE

[froooze]

General

Closes #[Insert issue number]

[Insert description of what you did, any description how to test or check your changes are welcome]

General

Please make sure the following is done:

• Pull request is onto develop
• If you haven't already, have a look at
  • https://github.com/bitshares/bitshares-ui/blob/develop/CODE_OF_CONDUCT.md
  • https://github.com/bitshares/bitshares-ui/blob/develop/CONTRIBUTING.md

Code Preparation

Please review all your changes one last time before committing

• Check for unused code
• No unrelated changes are included
• None of the changed files are reformatting only
• Code is self explanatory or documented
• All written text is properly translated (english language)

Testing

The branch has been tested on the following browsers (desktop and mobile view)

• Chrome
• Opera
• Firefox
• Safari

User interface changes

Delete this section if there weren't any UI changes. Please make sure you tested your changes in all themes

• Dark
• Light
• Midnight

Please provide screenshots/licecap of your changes below

[sschiessl-bcp]

Thanks