Warn <svg> may be skipped only when it is named but any role is given

[ymrl]

The svg-skip rule indicates <svg> element without <title> descendant, saying "May be skipped". But image-name rule says 'No <title> element' for almost same condition, these warnings are overlapped.

[ymrl]

I found that only "May be skipped" is shown for <svg> with aria-label attribute and no role attribute.
In this situation, <svg> element has graphics-document according to html-aam and svg-aam, but handled as having image role by Chrome. (in Firefox, as graphics-document) role.

[ymrl]

<svg> element with aria-label, and without any role:

• macOS VoiceOver + Safari / Chrome / Firefox: read the content of aria-label
• iOS VoiceOver + Safari: read as 'image', cannot read the aria-label
• NVDA + Chrome: read the content of aria-label
• NVDA + Firefox: read as 'blank', cannot read the aria-label

I think it is better to keep the rule. and need to more research the screen reader behaviors to <svg>

[ymrl]

Changed <svg> warning rule:

• no name and no role: No accessible name
• has name and no role: May be skipped