Blockquotes in markdown mode should always wrap/unwrap selected content

[Franck-Dernoncourt]

Reported on Meta.SE here.

Describe the bug
Lists are removed when quoted when in markdown mode and the blockquote menu button is clicked.

Expected behavior

The content should be wrapped instead of the block type being replaced. In most cases, replacing the block type is beneficial (unordered list -> ordered list), but in the majority of cases that blockquote is used, the user wants to quote the entire selected text as-is.

To Reproduce
Demo:

Desktop (please complete the following information):

• OS: Windows 7 SP1 x64 Ultimate
• Browser chrome

[b-kelly]

Thanks for the report! This is a very similar issue to #69 - they both are caused by the same underlying behavior.

[yellis]

@b-kelly since #69 was resolved, is this now resolved as well?

[b-kelly]

I may have misspoke. This one actually looks like a "feature" rather than a bug. The list items are considered a block type, therefore adding a different block type (in this case, blockquotes) replaces them.

Thinking on it, I think we want to leave this functionality in place for the most part, as that'll allow e.g. ordered lists to replace unordered lists, but we may want to instead treat blockquote specially. In most cases that I can think of, you'll always want a blockquote to wrap whatever you have highlighted instead of replacing it (as would be the case with headers, etc).

I'll edit the reported issue to reflect this.