Add `sqltools.disableChordKeybindings` setting to disable Ctrl/Cmd+E chords (#845)

[gjsjohnmurray]

This fixes #845. Previously the extension added a set of chord keybindings beginning withCtrl/Cmd+E. As a consequence users suddenly lost the ability to invoke VS Code's Go to File... command from the keyboard using its standard keybinding (Ctrl/Cmd+E).

This change adds a new setting sqltools.disableChordKeybindings and defaults it to false.

Also add the chord Ctrl/Cmd+E Ctrl/Cmd+E to invoke the masked command as long as focus is not on selected text in an editor.

While adding the new setting I also polished descriptions for other settings.

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[codecov[bot]]

Codecov Report

Merging #958 (27713a8) into dev (37c6ad0) will not change coverage. The diff coverage is 0.00%.

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  Coverage   10.00%   10.00%           
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  Files         175      175           
  Lines        5867     5867           
  Branches     1376     1376           
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  Hits          587      587           
  Misses       5280     5280           

Flag	Coverage Δ
extension	10.00% <0.00%> (ø)
formatter	100.00% <ø> (ø)

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Impacted Files	Coverage Δ
...connection-manager/dependency-manager/extension.ts	0.00% <0.00%> (ø)

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[mtxr]

@gjsjohnmurray the project is quite old and we don't have much reports about this, instead of making this a breaking change, why not make this an opt in setting to disable the chord instead?

Either way, I believe key bindings are easy to change. I started the project for VSCode because Sublime users were migrating (like I was) so I wanted to use my project from there (https://packagecontrol.io/packages/SQLTools) here, for the same reason MS team created a package to make it easier for sublime users to onboard on vscode (https://marketplace.visualstudio.com/items?itemName=ms-vscode.sublime-keybindings), so I have no idea if some users came here and still uses the key bindings I use, but a breaking change is always something that will affect daily work.

As you know, on my daily basis right now i'm not using sqltools often anymore, so would be a big deal to me, but it's still just one report, I believe we should open this for discussion with more developers, just don't know where

[gjsjohnmurray]

@mtxr coincidentally I had just reached the same conclusion about not making this a breaking change. I have pushed a commit which inverts the logic of the new (renamed) setting.