Before this commit, owl would incorrectly skip patching html properties
when the new value is the same as the value used in the previous render.
However, this is incorrect, since the user may have changed the value by
clicking on a checkbox, or changing some text in an input.
So, to be more correct, owl has to force the update whenever it
encounters a prop. This is however hard to do without impacting the
main update loop, so we kind of work around the problem by using String
and Boolean instance, instead of primitive values.
Previously, having a leading or trailing space caused
HTMLElement.classList.add to be called with an empty string (because we
are splitting on whitespace), which is not allowed and caused a crash.
This commit fixes that by trimming the keys of the class object in the
same way that we already do it for class strings.
Before this commit, the generated code crashed if an attribute in
the template contained backticks. The compiler output something
like
```js
let block1 = createBlock(`<div foo="`bar`"/>`);
```
The backticks are now properly escaped.