Update Network Mapping

Update network mapping (Note: name of network mapping cannot be changed)

Example of request:

curl --location --request PUT 'https://api.gcore.com/dns/v2/network-mappings/123' \
--header 'Authorization: Bearer ...' \
--header 'Content-Type: application/json' \
--data-raw '{
	"name": "test-mapping",
	"mapping": [
		{
			"tags": [
				"tag1"
			],
			"cidr4": [
				"192.0.2.0/24"
			]
		},
		{
			"tags": [
				"tag2",
				"tag3"
			],
			"cidr4": [
				"192.1.2.0/24"
			],
			"cidr6": [
				"aa:10::/64"
			]
		}
	]
}'