Insert nested selectors differently

[emmatown]

What:

Insert nested selectors differently

Why:

It's smaller than #386 and should be faster(We need to add benchmarks for highly dynamic values).

How:

If a selector is a parent it inserts itself before the rule with the parent and removes itself from the selectorQueue and if its not a parent it just inserts itself after the previous rule

Checklist:

• Documentation N/A
• Tests
• Code complete

[codecov]

Codecov Report

Merging #387 into master will decrease coverage by 0.03%.
The diff coverage is 100%.

Impacted Files	Coverage Δ
packages/emotion/src/index.js	100% <100%> (ø)	⬆️