[type: enhancement] On C# client generation: Convert description fields to XML comment syntax

[jeremia]

Description fields in Swagger can be in markdown or html. There are multiple cases where a markdown syntax och html syntax have a corresponding xml comment syntax. It would be nice if the generated XML comment (for summary, remarks, param and returns) would be converted to XML comment syntax.

This is related to #1171 and #1364.

XML Comments syntax: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/xmldoc/recommended-tags Markdown syntax: https://www.markdownguide.org/cheat-sheet/

Examples

Description	Markdown example	HTML example	XML Comment
Code	`asdf` | N/A | <c>asdf</c>
Code block	``` Console.WriteLine("asdf"); ``` | N/A | <code lang="csharp"> Console.WriteLine("asdf"); </code>
Unordered list	* a * b * c OR - a - b - c	<ul>  <li>a</li>  <li>b</li>  <li>c</li> </ul>	<list type="bullet">  <item>a</item>  <item>b</item>  <item>c</item> </list>
Ordered list	1. a 2. b 3. c	<ol>  <li>a</li>  <li>b</li>  <li>c</li> </ol>	<list type="number">  <item>a</item>  <item>b</item>  <item>c</item> </list>
Table	\| Heading 1 \| Heading 2 \| \| -- \| -- \| \| row1Value1 \| row1Value2 \|	<table>  <tr>   <th>Heading 1</th>   <th>Heading 2</th>  <tr>   <td>row1Value1</td>   <td>row1Value2</td>  </tr> </table>	<list type="table">  <listheader>   <term>Heading 1</term>   <term>Heading 2</term>  </listheader>  <item>   <term>row1Value1</term>   <term>row1Value2</term>  </item> </list>