fix: Broken examples problems when using inheritdoc tag

[filzrev]

This PR intended to fix problems that are reported by #9736, #9495.

When using example tag with <inheritdoc />.
symbol.GetDocumentationComment API returns slightly different format xml.
And it cause wrong metadata generation.

Problems of parsed results
1. Parsed example comments contains heading spaces.

It cause rendered as markdown as Fenced code blocks.

**2. HTML <pre> element without preceding line break cause wrong HTML output. **

This may be due to CommonMark specifications.
Because CommonMark/Markdig/GFM have same rendered result.
By this problem. it must be formatted as indented XML.

Example markdown code that reproduce problems

DUMMY<pre>{
  indended text
}</pre>

DUMMY
<pre>{
  indended text
}</pre>

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.99%. Comparing base (fe673ec) to head (9950416).
Report is 53 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9754      +/-   ##
==========================================
+ Coverage   74.31%   78.99%   +4.67%     
==========================================
  Files         536      536              
  Lines       23189    23186       -3     
  Branches     4056     4025      -31     
==========================================
+ Hits        17234    18316    +1082     
+ Misses       4853     3747    -1106     
- Partials     1102     1123      +21     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[filzrev]

Unit test code
Following unit test code should be added to samples/seed/dotnet/project/Project/Inheritdoc.cs.
(It need to add snapshot of *.html.verified.json files. But these files should be created by CI)

    public class Issue9736
    {
        public interface IJsonApiOptions
        {
            /// <summary>
            /// Whether to use relative links for all resources. <c>false</c> by default.
            /// </summary>
            /// <example>
            /// <code><![CDATA[
            /// options.UseRelativeLinks = true;
            /// ]]></code>
            /// <code><![CDATA[
            /// {
            ///   "type": "articles",
            ///   "id": "4309",
            ///   "relationships": {
            ///      "author": {
            ///        "links": {
            ///          "self": "/api/shopping/articles/4309/relationships/author",
            ///          "related": "/api/shopping/articles/4309/author"
            ///        }
            ///      }
            ///   }
            /// }
            /// ]]></code>
            /// </example>
            bool UseRelativeLinks { get; }
        }

        public sealed class JsonApiOptions : IJsonApiOptions
        {
            /// <inheritdoc />
            public bool UseRelativeLinks { get; set; }
        }
    }

[bkoelman]

Thanks. I can confirm this fixes the problem.