Update implicit role calculations in ARIAMapper

[carmacleod]

Updates data and code in ARIAMapper.elemToRoleMap/inputToRoleMap
to match the implicitRole data in ARIADefinitions.documentConformanceRequirement/documentConformanceRequirementSpecialTags
and the code in RPTUtil.getElementAriaProperty, which is called by RPTUtil.getImplicitRole.

The ARIADefinitions data and RPTUtil code were originally updated in #414 to match https://www.w3.org/TR/html-aria/ (which moved to W3C Rec status last week!) But the ARIAMapper data/code were not updated at that time.

It is unfortunate that this data and logic for implicitRole is duplicated because that makes it harder to maintain, so I have opened #573 to remove the redundancy some day.

Here are the changes that were needed in ARIAMapper:

• deleted menuitem element from all places it was refenced, because:
  a) it has not been supported in any browser for a long time (see https://developer.mozilla.org/en-US/docs/Web/HTML/Element/menuitem#browser_compatibility),
  b) menu element's role was changed to "list", which is not compatible with having children with role "menuitem"
• if input type="search" doesn't have a list, its implicit role is "searchbox", not "textbox"
• input type="password" does not have an implicit role (it is allowed to have attributes that are allowed on textbox - I will be adding a new machanism to cover that)
• body no longer has "document" role (it now has no implicit role). Instead, the html element has "document" role.
• dfn has role "term"
• dt has role "term"
• fieldset has role "group"
• figure has role "figure"
• footer: applied the same changes to header from Header bug: Failure if header parent is not an element (shadow dom?) #431
• form only has implicit role "form" (landmark) if it has an accessible name
• meter no longer has implicit "progressbar" role (Default role for meter should not be progressbar w3c/html-aria#44)
• section only has implicit role "region" (landmark) if it has an accessible name
• adds check for size="" to select implicit role calculation because parseInt("") returns NaN
• summary has implicit role "button"
• svg has implicit role "graphics-document"
• moved textarea to alphabetical order
• adds check for parent role === "treegrid" to td
• change a few == to ===

[tombrunet]

I think I need to update some of the testcases.