fix various extensions bugs to improve the basic-code-intel experience

[sqs]

I made these fixes while working on sourcegraph/code-intel-extensions#8.

Fixes #838

[codecov-io]

Codecov Report

Merging #1240 into master will decrease coverage by 0.01%.
The diff coverage is 71.42%.

Impacted Files	Coverage Δ
shared/src/api/client/context/contextService.ts	100% <ø> (ø)	⬆️
...ared/src/panel/views/HierarchicalLocationsView.tsx	0% <ø> (ø)	⬆️
shared/src/components/LinkOrButton.tsx	20% <ø> (ø)	⬆️
shared/src/actions/ActionItem.tsx	12.69% <0%> (-0.21%)	⬇️
shared/src/api/extension/api/configuration.ts	87.5% <100%> (ø)	⬆️
shared/src/api/client/services/location.ts	77.77% <100%> (+2.16%)	⬆️
shared/src/commands/commands.ts	32.55% <60%> (-4.95%)	⬇️

[lguychard]

This is getting pretty hard to parse, and the reasoning behind all the cases you're checking for isn't clear. I suggest extracting this logic and making it more explicit, eg:

const groupsToDisplay = GROUPS.filter(({ name, key }, i) => {
    // No locations were returned for this group - don't display it
    if (!groups[i]) {
        return false
    }
    // Always display file groups
    else if (groupByFile && name === 'file') {
        return true
    }
    ...
})

return (
    <div className={`hierarchical-locations-view ${this.props.className || ''}`}>
        {selectedGroups && groupsToDisplay.map(({ name, defaultSize }, i) => {
            ...
         })}

[sqs]

Good call. I will make this code much clearer.

[sqs]

@lguychard Thanks for the review! Updated, PTAL.

[lguychard]

LGTM