fix(DASH): Fix EventStream Elements creation

[tykus160]

Related to #7148
Does not create parent elements anymore to reduce memory consumption.
Starts to use createElementNS() so created elements will keep proper cases for tag names and they won't be anymore of type HTMLElement, but Element, which should be more lightweight and suitable for our needs.

[avelad]

@willdharris can you review it? Thanks!

[shaka-bot]

Incremental code coverage: 87.50%

[willdharris]

1. I do see improvement in terms of the number of Detached Elements created and retained.

v4.10.9

fix

2. However, that's not translating to an overall improvement in memory usage. Memory looks about the same between 4.10 and this fix.

Chrome Desktop - DASH LTS - JS Memory

Time | v4.7.15 | v4.10.9 | EventStream Fix
30min | 21MB | 123MB | 122MB
60min | 31MB | 223MB | 224MB
90min | 41MB | 337MB | 341MB

This PR looks beneficial but doesn't resolve the memory issues reported. I will add further detail in #7148.

[theodab]

It sounds like this doesn't completely fix the problem, but it at least looks like a good start.

[zelalami]

Hello @tykus160
After updating to the latest changes from this PR, I'm encountering an issue related to the createElementNS function. Specifically, I'm getting the following error:

[Failed to execute 'createElementNS' on 'Document': The namespace URI provided ('') is not valid for the qualified name provided ('scte35:Signal').]

This error occurs when parsing the following EventStream section of my DASH manifest:

<?xml version="1.0" ?>
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:scte35="urn:scte:scte35:2014:xml+bin" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" profiles="urn:mpeg:dash:profile:isoff-live:2011,urn:hbbtv:dash:profile:isoff-live:2012" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" publishTime="2024-08-28T09:27:58Z" minBufferTime="PT6S" type="dynamic" availabilityStartTime="1970-01-01T00:00:00Z" timeShiftBufferDepth="PT1M1.88S" minimumUpdatePeriod="PT6S" suggestedPresentationDelay="PT12S">
	<Period id="1" start="P19963DT9H26M52.407S">
		...
	</Period>
	<Period id="2" start="P19963DT9H27M50.807S">
		...
	</Period>
	<Period id="3" start="P19963DT9H27M54.287S">
		<EventStream schemeIdUri="urn:scte:scte35:2014:xml+bin" timescale="90000">
			<Event presentationTime="0" duration="2700000" id="1">
				<scte35:Signal>
					<scte35:Binary>.....</scte35:Binary>
				</scte35:Signal>
			</Event>
		</EventStream>
	</Period>
</MPD>