Fix hover hint for complex expressions

[toinehartman]

This fixes #268, by changing the lookup of ranges such that type hints/definitions will be shown for the smallest possible tree.

• Use a tree-based data structure based on containment instead of ordering for TreeMapLookup.
• Remove duplicate function for checking Range containment.

Building on this, I have been working a revised data structure that relies on containment instead of ordering. Since that requires more testing and checking guarantees/invariants, it now lives on a separate branch: https://github.com/usethesource/rascal-language-servers/tree/fix/range-lookup.

[DavyLandman]

Building on this, I have been working a revised data structure that relies on containment instead of ordering. Since that requires more testing and checking guarantees/invariants, it now lives on a separate branch: https://github.com/usethesource/rascal-language-servers/tree/fix/range-lookup.

I started out with such a structure, and I think I remember I ran into the problem of overlapping ranges and how to store them in such a tree in a way that you don't need to always go "left" and "right" in the tree. And primarily, I didn't want to keep around a complex data structure if we could get it to fit into a regular map.

An alternative strategy that @jurgenvinju has proposed in the past is to use the parse tree, and use code similar to the focus list building/semantic token highlighter.

But that has the downside that we would be iterating over the tree towards the leaf, and then depth first doing a map lookup in the list of hovers/definitions/... for every parent of the leaf untill we find a match. So not taking the shape of three into account during lookup.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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