Debugger improvements

[LianaHus]

• [ ] "Loaded address" does not always follow inter-contract calls (https://github.com/ethereum/remix-project/issues/276)
• [ ] Mark call types on slider (https://github.com/ethereum/remix-project/issues/170)
• [ ] Storage debugging should have an option to load every key (https://github.com/ethereum/remix-project/issues/250)
• [ ] to force Remix to use a specific solidity source code (https://github.com/ethereum/remix-project/issues/149)
• [x] Fix debugger navigation panel (https://github.com/ethereum/remix-project/issues/688)
• [x] Grid the debugger view components (https://github.com/ethereum/remix-project/issues/2712)