Split ElementTagNameMap and remove it

[falsandtru]

Some tag names of HTML and SVG are conflicted. So merging these two is wrong. ElementTagNameMap has to split into HTMLElementTagNameMap and SVGElementTagNameMap.

For example, a tag is defined in both HTML and SVG.

https://developer.mozilla.org/en-US/docs/Web/HTML/Element
https://developer.mozilla.org/en-US/docs/Web/SVG/Element

So the result type of document.querySelector('a') is defined as HTMLAnchorElement by TypeScript, but the actual type is HTMLAnchorElement | SVGAElement.

related: #14783