Deploy & Run: all the contracts in the workspace are not needed to appear in list

[ryestew]

Describe the bug
There is a report that we have too much info in Deploy & Run. Having all the contracts in the workspace appear, gives too much info and makes the plugin more confusing. While the spirit of providing more contracts in D&R was admirable, the effect makes the plugin present too much info. Also the imported contracts take up a lot of space - so adding all the contracts in the workspace, makes it more confusing.

To Reproduce
Steps to reproduce the behavior:

1. Have a workspace full of contracts
2. go to Deploy & Run
3. click the Contract select box at the top of the Deploy section.

Expected behavior
I'd expect that only the contracts in the .sol file or imported contracts to be there - not the other contracts in the workspace.
In terms of directing people to this select box, it is not named like it was in the previous version (where it was called "Contracts"). So now it is harder to explain to users what to click on.

And with all the contracts in a limited space, a user needs to navigate between two different vertical scroll bars:

@solangegueiros - anything to add here?