Setting optional props with base expr fails without `Some(...)`

[Xavientois]

Problem

Adding the following test to /yew-macro/tests/html_macro/component-pass.rs fails tests. This is due to the current implementation of property setting with a base expression.

This test passes if the property is wrapped in a Some, but

              <Container int=1 ..props>
                  <Child int=2 opt_str="hello" ..child_props />
              </Container>

Steps To Reproduce
Steps to reproduce the behavior:
Add the above snippet to line 213 of component-pass.rs

Expected behavior
Test passes and optional string it set in prop

Screenshots

Environment:

• Yew version: master
• Rust version: 1.53.0

Questionnaire

• I'm interested in fixing this myself but don't know where to start
• I would like to fix and I have a solution
• I don't have time to fix this right now, but maybe later