Improve the loading indicator

[efonsecab]

Currently, the loading indicator is implemented as an independent component, and is explicitly where it is required to be show, the current implementation however, makes it so that the html is rendering as a child of other components, so in smaller containers the indicator is not displayed over the whole screen, and only on the parent container. We need to modify this behavior, so that the loading indicator overlay is always displayed over the whole screen, even over the header and footer.

We need to research the best way to do this without using javascript.