When using "virtual directory" the api calls sometimes fail

[noam-honig]

Describe the bug
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the default value of apiBaseUrl = '/api'; is problematic when using baseURL='/xx/index.html'
On the other hand, if it's set to api it fails if you have nested routes in the app. (ie '/customersPage/1')

We should find some solution for the default value of apiBaseUrl that will support both nested routes, and apps that reside in a virtual directory.

To Reproduce
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4. See error

Expected behavior
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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
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