wip: Create subdomains via GuCname

[akash1810]

Checking that (random) subdomains can be created via GuCname.

Once deployed, https://lambda.cdk-playground.gutools.co.uk should resolve (though will serve a certificate for cdk-playground-lambda.gutools.co.uk as this PR doesn't tweak the certificate attached to the API Gateway that's the origin for this record).

Once main is deployed, the DNS record will be removed again.

dig result, demonstrating the record was created:

➜ dig lambda.cdk-playground.gutools.co.uk

; <<>> DiG 9.10.6 <<>> lambda.cdk-playground.gutools.co.uk
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18067
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;lambda.cdk-playground.gutools.co.uk. IN	A

;; ANSWER SECTION:
lambda.cdk-playground.gutools.co.uk. 3600 IN CNAME d-8aft3t6gvc.execute-api.eu-west-1.amazonaws.com.
d-8aft3t6gvc.execute-api.eu-west-1.amazonaws.com. 60 IN	A 52.210.221.239
d-8aft3t6gvc.execute-api.eu-west-1.amazonaws.com. 60 IN	A 34.240.242.137
d-8aft3t6gvc.execute-api.eu-west-1.amazonaws.com. 60 IN	A 34.249.54.28

;; Query time: 63 msec
;; SERVER: 192.168.50.1#53(192.168.50.1)
;; WHEN: Fri Dec 15 11:18:12 GMT 2023
;; MSG SIZE  rcvd: 342

[akash1810]

Redeploying main as this test is done now.

Also closing the PR.