[C#] Fixes array TypeDeclaration parsing order to fix deep aliases

[Mattias-Sehlstedt]

fixes: #21605

Adjusts the CSharp TypeDeclarationCodegen to properly parse a deep alias chain (currently it only traverses to a depth of 1). I have used the same structure as the JavaCodegen.

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[devhl-labs]

Thank you for the PR. If this PR is merged we should leave the issue open since there are still some errors after this change. I was going to make this code from the abstract recursive to fix the remaining generic issues, but it seems like a work around to a bug. Maybe you know a better way.

        String[] nestedTypes = {"List", "Collection", "ICollection", "Dictionary"};

        Arrays.stream(nestedTypes).forEach(nestedType -> {
            // fix incorrect data types for maps of maps
            if (property.datatypeWithEnum.contains(", " + nestedType + ">") && property.items != null) {
                property.datatypeWithEnum = property.datatypeWithEnum.replace(", " + nestedType + ">", ", " + property.items.datatypeWithEnum + ">");
                property.dataType = property.datatypeWithEnum;
            }

            if (property.datatypeWithEnum.contains("<" + nestedType + ">") && property.items != null) {
                property.datatypeWithEnum = property.datatypeWithEnum.replace("<" + nestedType + ">", "<" + property.items.datatypeWithEnum + ">");
                property.dataType = property.datatypeWithEnum;
            }
        });

[Mattias-Sehlstedt]

The author of the original issue was not very elaborate on exactly what issues they faced.

I have created a separate issue for the deep alias problem which I have attempted to fix. I have updated the PR description to refer to that issue instead.