ignore image refs failing

[himynamesdave]

https://github.com/muchdogesec/txt2stix/blob/issue-with-ignores/tests/manual-tests/cases-standard-tests.md#ignore-image-refs

Input file

<img href="https://www.google.com/image.png" alt="tiktok.com" />

![facebook.com](https://www.twitter.com/image.png)

instagram.com

Should ignore https://www.twitter.com/image.png and https://www.google.com/image.png

python3 txt2stix.py \
	--relationship_mode standard \
	--input_file tests/data/manually_generated_reports/embedded_img_ignore.txt \
	--name 'ignore image refs true' \
	--tlp_level clear \
	--confidence 100 \
	--use_extractions pattern_domain_name_only,pattern_domain_name_subdomain,pattern_url,pattern_file_name \
	--ignore_image_refs true \
	--report_id 649da017-4090-48b2-97da-b24d37418ee6

but see extractions

data--649da017-4090-48b2-97da-b24d37418ee6.json

Only

instagram.com

extracts. but script should only ignore image link (not alt tags, etc.) So expected extractions are

instagram.com
tiktok.com
facebook.com

[fqrious]

As such we should add flag ignore_image_refs which will ignore all content inside HTML or markdown image tags

I was asked to completely remove the image in the original issue.

img tags do not have hrefs, they have srcs, so all but the twitter link will be extracted after this change is implemeted.