FEAT: Add a title attribute to the Layers panel elements

Hi @artf ,

When I have several elements nested in the Layers panel then some elements names are truncated because the Layer panel's width is not big enough, I know that custom resizable panel can be a solution but adding a title attribute would be enough for the majority of the use cases.

A tooltip (title) would be helpful to the user.

grapesjs/src/navigator/view/ItemView.js May be adding a title attribute to the follow line can do the job? https://github.com/artf/grapesjs/blob/7a23e20fe5138c37088ef05382f7c759cb6fa951/src/navigator/view/ItemView.js#L47

Example:

<div class="${pfx}layer-title-inn" title="${name}">

Let me know what do you think,

Thanks!