Check behavior of server with Icons and websiteUrl metadata added as part of SEP-973 specification.

check modelcontextprotocol/go-sdk/issues/552 for more details.

Checks following:
- Test setting websiteUrl, icons for mcp.Implementation
- Test setting icons for mcp.Prompt
- Test setting icons for mcp.Tool
- Test setting icons for mcp.Resource
- Test if tool call returning ResourceLink with icons works as expected


-- tools --
greetWithIcon
contentTool

-- prompts --
code_reviewWithIcon

-- resources --
infoWithIcon

-- client --
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {
    "protocolVersion": "2025-06-18",
    "capabilities": {},
    "clientInfo": { "name": "ExampleClient", "version": "1.0.0" }
  }
}
{ "jsonrpc": "2.0", "method": "notifications/initialized" }
{ "jsonrpc": "2.0", "id": 2, "method": "tools/list" }
{ "jsonrpc": "2.0", "id": 3, "method": "resources/list" }
{ "jsonrpc": "2.0", "id": 4, "method": "prompts/list" }
{
	"jsonrpc": "2.0",
	"id": 5,
	"method": "tools/call",
	"params": {
		"name": "contentTool",
		"arguments": {
			"In": "resource1"
		}
	}
}

-- server --
{
	"jsonrpc": "2.0",
	"id": 1,
	"result": {
		"capabilities": {
			"logging": {},
			"prompts": {
				"listChanged": true
			},
			"resources": {
				"listChanged": true
			},
			"tools": {
				"listChanged": true
			}
		},
		"protocolVersion": "2025-06-18",
		"serverInfo": {
			"name": "testServer",
			"version": "v1.0.0",
			"websiteUrl": "https://github.com/modelcontextprotocol/go-sdk",
			"icons": [
				{
					"src": "foobar",
					"mimeType": "image/png",
					"sizes": [
						"48x48",
						"96x96"
					],
					"theme": "light"
				}
			]
		}
	}
}
{
	"jsonrpc": "2.0",
	"id": 2,
	"result": {
		"ttlMs": 0,
		"cacheScope": "public",
		"tools": [
			{
				"description": "return resourceLink content with Icon",
				"inputSchema": {
					"type": "object",
					"properties": {
						"In": {
							"type": "string",
							"description": "the input"
						}
					},
					"required": [
						"In"
					],
					"additionalProperties": false
				},
				"name": "contentTool",
				"title": "contentTool"
			},
			{
				"description": "say hi",
				"inputSchema": {
					"type": "object",
					"properties": {
						"Name": {
							"type": "string"
						}
					},
					"required": [
						"Name"
					],
					"additionalProperties": false
				},
				"name": "greetWithIcon",
				"icons": [
					{
						"src": "foobar",
						"mimeType": "image/png",
						"sizes": [
							"48x48",
							"96x96"
						],
						"theme": "light"
					}
				]
			}
		]
	}
}
{
	"jsonrpc": "2.0",
	"id": 3,
	"result": {
		"ttlMs": 0,
		"cacheScope": "public",
		"resources": [
			{
				"mimeType": "text/plain",
				"name": "info",
				"uri": "embedded:info",
				"icons": [
					{
						"src": "foobar",
						"mimeType": "image/png",
						"sizes": [
							"48x48",
							"96x96"
						],
						"theme": "light"
					}
				]
			}
		]
	}
}
{
	"jsonrpc": "2.0",
	"id": 4,
	"result": {
		"ttlMs": 0,
		"cacheScope": "public",
		"prompts": [
			{
				"arguments": [
					{
						"name": "Code",
						"required": true
					}
				],
				"description": "do a code review",
				"name": "code_review",
				"icons": [
					{
						"src": "foobar",
						"mimeType": "image/png",
						"sizes": [
							"48x48",
							"96x96"
						],
						"theme": "light"
					}
				]
			}
		]
	}
}
{
	"jsonrpc": "2.0",
	"id": 5,
	"result": {
		"content": [
			{
				"type": "resource_link",
				"mimeType": "text/plain",
				"uri": "https://example.com/resource/resource1",
				"name": "Example Resource Link with Icons",
				"icons": [
					{
						"src": "foobar",
						"mimeType": "image/png",
						"sizes": [
							"48x48",
							"96x96"
						],
						"theme": "light"
					}
				]
			}
		]
	}
}