Simplify location URLs if start and end line are the same

[Marcono1234]

When the start and end line of a result are the same, currently the extension creates location URLs which specify both line numbers, e.g. ...MyFile.js#L5-L5. This is appears to be redundant and can be simplified to just #L5.

I am not very familiar with this project, so any feedback is appreciated!

Checklist

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[aeisenberg]

This looks great. Thank you for your contribution. One minor thing I would like to see is that with this change is that the test is no longer showing any multiline results (arguably this was a limitation of the test before, but there was only a single code path earlier). But, could you add at least one multiline result in one of the test files, like result-1-github-codeql.md? You'd also need to update the corresponding test input in analyses-results.json. I think this is straight forward, but if not, I can take a look.

[aeisenberg]

Failing test is likely a flake.

[Marcono1234]

One minor thing I would like to see is that with this change is that the test is no longer showing any multiline results

I am not completely sure what you mean. If you had written "still shows multiline results", then I would have assumed you mean that something like #L1-L5 is unaffected, and that actually appears to be the case, see for example:

vscode-codeql/extensions/ql-vscode/test/unit-tests/data/markdown-generation/interpreted-results/path-problem/expected/result-2-meteor-meteor.md

Line 51 in 788eb2b

5. [npm-packages/meteor-installer/install.js](https://github.com/meteor/meteor/blob/73b538fe201cbfe89dd0c709689023f9b3eab1ec/npm-packages/meteor-installer/install.js#L11-L23)

vscode-codeql/extensions/ql-vscode/test/unit-tests/data/markdown-generation/interpreted-results/problem/expected/result-1-github-codeql.md

Line 3 in 788eb2b

[javascript/extractor/tests/regexp/input/multipart.js](https://github.com/github/codeql/blob/d094bbc06d063d0da8d0303676943c345e61de53/javascript/extractor/tests/regexp/input/multipart.js#L17-L20)

So, what did you mean by "no longer showing any multiline results"?

[aeisenberg]

Apologies for that. You are correct. I missed those extra tests. Thanks for pointing them out. This PR looks great.