Fix for cke5 to allow link attributes

[LordRembo]

Q	A
Bug fix? (use the a.b branch)	[x]
New feature/enhancement? (use the a.x branch)	[ ]
Deprecations?	[ ]
BC breaks? (use the c.x branch)	[ ]
Automated tests included?	[ ]
Related user documentation PR URL	mautic/mautic-documentation#...
Related developer documentation PR URL	mautic/developer-documentation#...
Issue(s) addressed	Fixes #13724

Description:

This partly reenables a feature that was present in Mautic 4: allowing for more html and html properties (attributes) to be printed inside CKE.
This change is limited to:

• attributes on Links
• allowing the use of span tags, with attributes (used by some email template makers for special highlights in placeholder text or even to override link colors)

I also had to upgrade CKE (went from v38 to 41 ), because there was a bug that gave duplicate module errors when trying to import and add certain plugins.

When editing the contact block in the Brienz theme (and similar issues will arise in people's custom themes), the CKEditor gave a blank textarea, instead of letting you edit the existing text.
This was caused by some html attributes being in the prefilled Text Block. Instead of just the attributes being filtered out, the entire content disappeared.

Read the full bug report here

Steps to test this PR:

1. Open this PR on Gitpod or pull down for testing locally (see docs on testing PRs here)
2. Create a new emails
3. Use the Brienz theme
4. Open the contact block
5. The content in CKE is not empty
6. Add a bit of text, and save it
7. Your preview shows the changed text
8. Extra: if you inspect the Block in the Browser (using dev tools), you should see that the links (eg. for phone and email) still contain a title attribute (we don't really care for the ID or the 'draggable' attributes as they are set by the system for interaction and not by the user).
9. Test that the other functionalities of CKE still work, eg. in another Text block: make some bold text, make a list, a link, adding a Token, …

[escopecz]

I see no issues in the code. It fits the PR description, updates a lot of JS dependencies that all seem to be related to CK editor 👍

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.51%. Comparing base (a98a30f) to head (58963d6).

Additional details and impacted files

@@             Coverage Diff              @@
##                5.x   #13725      +/-   ##
============================================
- Coverage     61.51%   61.51%   -0.01%     
  Complexity    34068    34068              
============================================
  Files          2241     2241              
  Lines        101852   101852              
============================================
- Hits          62651    62650       -1     
- Misses        39201    39202       +1     

see 1 file with indirect coverage changes

[abhisekmazumdar]

Tested locally, I can confirm it resolved the issue mentioned here: #13724.