fix/54877: Allow insertion of Buttons in the Navigation Block

[Sidsector9]

What?

In this PR, the directInsert prop is set to false to enable insertion of other supported blocks.

Why?

It is counter-intuitive to insert a custom link, and then transform it into a Button, instead of adding a Button just how one would using the default inserter. This fix reduces confusion and improves user experience.

How?

Testing Instructions

In trunk

1. Add a Navigation Block
2. Add custom link to the Nav block.
3. Click the inserter within the Nav Block and see you don't get the option to add the Buttons block.
4. Switch to the fix branch and repeat 1, 2 and 3
5. Observe you get the default inserter to insert the Buttons Block.

Screenshots or screencast

Screen.Recording.2023-10-06.at.6.37.55.PM.mov

[alexstine]

Why would you need to add a button to the navigation block in the first place? Just wondering. I forget, does it output an actual <button> or <a>?

[hanneslsm]

Why would you need to add a button to the navigation block in the first place? Just wondering. I forget, does it output an actual or ?

Just visuals, I guess. Like "Sign up now".
The output is <a>

<div class="wp-block-button">
<a class="wp-block-button__link wp-element-button">Sign up now</a>
</div>

[getdave]

Thank you for the PR. At first glance the motivation seems solid.

However, I know we need to be pretty careful with amending the values in this PR so leaving a blocking review until I have chance to review in greater depth.

[t-hamano]

I just wanted to add that #55144 has also been submitted, which takes a slightly different approach to this PR.

[getdave]

It is my opinion that if we want to add this feature then #55144 is the way to go.

Thank you for the PR but I think we should close it out 🙏

[Sidsector9]

Closing as discussed.