Allow for EML and MSG parsing / also check+replace if fileName has "#" character

[kachihro]

Purpose

We had a requirement to ingest EMAIL files, EML and MSG. This required a new 'parser' - as well as a new component to display the email, when selected.

Another issue was the "#" character in some fileNames - they would ingest OK, but couldn't use the HREF due to the # within the fileName/Url - rather than DOC.PDF#page1

This PR includes an additional package for the 'extract-msg' - and some CSS tweaks also (for showing MAIL)

Does this introduce a breaking change?

Have been able to deploy via "AZD DEPLOY" and the processing of EML/MSG files is working - and can view them after a chat or ask response. ✅

[ X ] Yes
[ ] No

## Does this require changes to learn.microsoft.com docs?
No changes to deployment instructions - perhaps need to include details that EML and MSG are supported types.

[ X ] Yes
[ ] No

Type of change

[ X ] Bugfix - with fileName containing "#"
[ X ] Feature - able to ingest EML and MSG
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe: