Eliminate navigateMode location in next major release

[techfg]

Is your feature request related to a problem and/or adding functionality? Please describe.
V1.5.0 introduced the navigationMode configuration option. In the next major release, support for navigationMode of location should be removed as the legacy use of window.location.href had a number of limitations/issues as described in #353. Moving forward, open should be the default behavior.

One additional consideration would be to add a new mode of default. This mode would inform IM to not navigate but rather allow the click to bubble up to the browser and let the browser handle the navigation. Its possible that only default mode is even required and 'open' could be eliminated completely. The only drawback to this is that the HTML would be required to have href & target attributes on every AREA element - currently IM provides an assist here because of the AreaData concept. Technically speaking though, the absense of href attribute is bad for accessibility so really the HTML should contain an href value on every AREA element and not rely on IM to "use the default href for the AreaData."

Describe the solution you'd like
Eliminate location mode support for navigationMode and consider adding default and even eliminating open.

Describe alternatives you've considered
N/A

Additional context
N/A