[Docs] Update migration guide for Connector/NET

[rbanks54]

I've updated the docs as there was a Connector/NET issue (70111) resolved in a recent update that wasn't reflected in the migration guide.

I also found it difficult looking through the list of bugs to see which were open/closed given all the strikethrough content. As such I reordered the list to make it easier to see; grouping the open and closed items whilst retaining the issue number ordering.

Finally, I updated the migration docs for a handful of other issues to indicate which C/NET version a problem was fixed in. Coming from an older C/NET version, I would have found it quite useful to know which bug fixes weren't relevant and which ones I needed to pay attention to.

[bgrainger]

Thanks for the contribution to the docs!

[bgrainger]

found it difficult looking through the list of bugs to see which were open/closed given all the strikethrough content. As such I reordered the list to make it easier to see; grouping the open and closed items whilst retaining the issue number ordering.

Now that the fixed-first bugs are in their own section (great idea BTW), the strikethrough feels very unnecessary (and makes the text difficult to read) so I just removed it all: dd518bf

Thanks again.