chore: rename test fixtures

[wjhsf]

Some of the directory names were too sentence-y, which made them annoying to work with.

List of new names, since the diff isn't helpful

adapter-function-identifier-works
adapter-member-expression-works
basic-field
basic-method
config-ignores-method
config-ignores-spread
config-imported-values-works
config-multiple-dynamic-params-works
config-not-provided-works
config-numeric-keys-works
config-string-literal-keys-works
decorating-multiple-props-works
decorator-on-getter-alone-works
decorator-on-getter-works
decorator-on-setter-alone-works
decorator-on-setter-works
reactive-string-2-levels-works
reactive-string-deep-chain-works
reactive-string-with-empty-segment-works
reactive-string-with-non-identifier-works
throws-on-2-wires
throws-on-adapter-computed-prop
throws-on-adapter-function-expression
throws-on-adapter-local-var
throws-on-adapter-nested-member-expression
throws-on-adapter-undeclared-var
throws-on-config-not-object
throws-on-decorator-no-args
throws-on-wired-method-with-@api
throws-on-wired-prop-with-@api
throws-on-wired-prop-with-@track
throws-when-computed-prop-is-expression
throws-when-computed-prop-is-let-variable
throws-when-computed-prop-is-regexp-literal
throws-when-computed-prop-is-template-literal
transforms-computed-properties
transforms-computed-properties-const-from-obj

I didn't update the computed prop names because I'm planning on changing them anyway in my next PR.

Details

Does this pull request introduce a breaking change?

• 😮‍💨 No, it does not introduce a breaking change.
• 💔 Yes, it does introduce a breaking change.

Does this pull request introduce an observable change?

• 🤞 No, it does not introduce an observable change.
• 🔬 Yes, it does include an observable change.

GUS work item