Fix #74523

We are ok with tests throwing on undefined access, so use the not null assertion heavily here

We set alwaysStrict so this directive is not needed

fuzzyScore - allow passing of lower-case variants of things, allow passing of start positions, move whitespace starts to completion model

Standardizing syntax and discouraging use of `this` inside tests

make fuzzy score more strict and don't treat a match on a subsequent upper case latter as stong match (but as simple match),  #50724

Comparing `const` with `constructor` and `const` should favor the latter.
Even tho both are prefix matches, the latter is a perfect match and that
should be accounted for.

This reverts commit 093eac50.