Werk #15288: Remove HTMLGenerator.add_default_javascript function

MKPs that use custom javascript code may be affected by this change. A typical usage of this function may look like:

html.add_default_javascript("custom_id")

There is no 1:1 replacement for this call, but several ways to do similar things:

html.javascript("inlined_javascript_code();")

html.javascript_file("browser/path/to_javascriptfile.js")

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