Use explicit case-insensitive attribute-value matching in UA-stylesheets

With the "i" (case-insensitive) matching modifier introduced in
https://codereview.chromium.org/330043003/, it becomes possible to
refine the hits on the CaseInsensitiveAttrSelectorMatch use-counter
by applying the modifier to all rules in the UA-stylesheets which
perform an attribute-value match on one of the attributes that - due
to legacy reasons - should be matched case-insensitively.

Most of the modified rules involve the 'type' attribute on <input>
elements, but there are a few others as well ('dir' and 'align').

The goal of this is to be able to get rid of the legacy-induced case-
insensitive cases and leave the "i" flag as a mechanism to opt-in to
case-insensitive matching. See https://crbug.com/327060 for further info.

BUG=327060, 366563

Review URL: https://codereview.chromium.org/417353004

git-svn-id: svn://svn.chromium.org/blink/trunk@179401 bbb929c8-8fbe-4397-9dbb-9b2b20218538