fix: contain name escape backslash

[gwnlng]

escape backslash in contain-name search string

Testcase

(snyk-tags-xVW0Mbl0-py3.9) gwunleong@gwunleongs-MBP snyk-tags-tool % python3 -m snyk_tags tag alltargets --contains-name="io.snyk\log4shell\server" --group-id=ff0c78bb-6365-462c-8576-e73de8793870 --org-id=84a533fd-4686-451f-9c36-af3b30332670 --tagkey=app-microservice --tagvalue=io-snyk-log4shell

Adding the tag key app-microservice and tag value io-snyk-log4shell to io.snyk\log4shell\server projects in Snyk for easy filtering via the UI
Successfully added io-snyk-log4shell tag to Project: c:\io.snyk\log4shell\server.

(snyk-tags-xVW0Mbl0-py3.9) gwunleong@gwunleongs-MBP snyk-tags-tool % python3 -m snyk_tags remove tag-from-alltargets --contains-name="io.snyk\log4shell\server"  --org-id=84a533fd-4686-451f-9c36-af3b30332670 --tagkey=app-microservice --tagvalue=io-snyk-log4shell 

Removing app-microservice:io-snyk-log4shell from projects within 84a533fd-4686-451f-9c36-af3b30332670
Removing tag app-microservice:io-snyk-log4shell from c:\io.snyk\log4shell\server