Remove breadcrumbs for multistore homepage

[PingusPepan]

When there are multiple different cms home pages with same identifier but for different store views, breadcrumbs are shown in all of them except the first.
The same applies for 404 pages.
Fixes #6504

[skovalenk]

@PingusPepan Hi, Ill appritiate if you explain to me how spliting string by | delimiter, helps to find home page identifier. I Suppose you have some sequence such as "home_page_id|something_else". However by default Magento dont have this functionality

[PingusPepan]

@sereban I copied this exact code from Magento 2 core code and just altered it for homepage and 404 recognition.
You can find the original code I copied this from in the file: (app/code/Magento/Cms/Helper/Page.php:125)

I think the | delimiter is applied when there are multiple pages for different store views with same identifiers and this helps to identify them by id.

[PingusPepan]

You can see where and why this happens in file app/code/Magento/Cms/Model/ResourceModel/Page/Collection.php:57

If there are two same identifiers, it adds the delimiter. That's fine, it just wasn't accounted for in the breadcrumbs homepage and 404 check code. I only added the check for it and now it works just fine. #6504 is fixed by this PR. The delimiter lives only in config so it can't be seen while editing the page or in cms database table.

[skovalenk]

@PingusPepan Ok So if there is identifier and page title for home page than they save with delimiter. Cool. Thanks. We will see PR.

[PingusPepan]

Has anyone looked into this? It's a simple bug fix and it would help to have it fixed in Magento. This way I have to manually replace the file after every test install/update

[magento-team]

@PingusPepan Thank you for the contribution