feat/refactor: rewrite webhook-handler

[shreddedbacon]

General Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for inclusion in changelog

Database Migrations

• If your PR contains a database migation, it MUST be the latest in date order alphabetically

Description

This is a substantial rewrite of the webhook-handler which consolidates the webhook-handler and webhooks2tasks services. Additionally, the API will now call out to the api-sidecar-handler service to handle triggering deployments and environment removals, this allows for shared code between the webhook-handler and api-sidecar-handler.

One way this is done is by moving from individual go services with their own go.mod files, into a mono repo setup. There are some remaining services that will need to be converted in a follow up pullrequest though. I left them out of this to try to reduce the amount of changes.

Builds off fork of drone/go-scm, which we can try to get merged into upstream.

Requires uselagoon/lagoon-charts#858

[github-actions]

Overview

Image reference	testlagoon/api:main	lagoon/api:ci-latest
- digest	a9ca7509afa5	57a979513241
- tag	main	ci-latest
- provenance	https://github.com/uselagoon/lagoon.git/commit/e3b3e65eff5102d4349ee8819537857607c6a372
- vulnerabilities
- platform	linux/amd64	linux/amd64
- size	151 MB	170 MB (+20 MB)
- packages	1579	1490 (-89)
Base Image	node:22-alpine also known as: • 22-alpine3.23 • 22.22-alpine • 22.22-alpine3.23 • 22.22.0-alpine • 22.22.0-alpine3.23 • jod-alpine • jod-alpine3.23	node:22-alpine also known as: • 22-alpine3.23 • 22.22-alpine • 22.22-alpine3.23 • 22.22.0-alpine • 22.22.0-alpine3.23 • jod-alpine • jod-alpine3.23
- vulnerabilities

Packages and Vulnerabilities (77 package changes and 6 vulnerability changes)

• ➖ 68 packages removed
• ♾️ 9 packages changed
• 1261 packages unchanged

• ✔️ 6 vulnerabilities removed

Changes for packages of type apk (5 changes)

	Package	Version testlagoon/api:main	Version lagoon/api:ci-latest
♾️	alpine-base	3.23.2-r0	3.23.3-r0
♾️	alpine-release	3.23.2-r0	3.23.3-r0
♾️	libcrypto3	3.5.4-r0	3.5.5-r0
♾️	libssl3	3.5.4-r0	3.5.5-r0
♾️	openssl	3.5.4-r0	3.5.5-r0
		Removed vulnerabilities (4):

Changes for packages of type npm (72 changes)

	Package	Version testlagoon/api:main	Version lagoon/api:ci-latest
➖	@postman/form-data	3.1.1
➖	@postman/tough-cookie	4.1.3-postman.1
➖	@postman/tunnel-agent	0.6.4
➖	asn1	0.2.6
➖	assert-plus	1.0.0
➖	aws-sign2	0.7.0
➖	aws4	1.13.2
➖	bcrypt-pbkdf	1.0.2
➖	bluebird	2.11.0
➖	brotli	1.3.3
➖	caseless	0.12.0
➖	chardet	2.0.0
➖	charset	1.0.1
➖	cli-progress	3.12.0
➖	cli-table3	0.6.5
♾️	commander	8.3.0	7.2.0
➖	core-util-is	1.0.3
➖	csv-parse	4.16.3
➖	dashdash	1.14.1
➖	des.js	1.1.0
➖	ecc-jsbn	0.1.2
➖	extend	3.0.2
➖	extsprintf	1.4.1
➖	file-type	3.9.0
➖	filesize	10.1.4
➖	forever-agent	0.6.1
➖	getpass	0.1.7
➖	har-schema	2.0.0
➖	har-validator	5.1.5
➖	http-reasons	0.1.0
➖	http-signature	1.3.6
➖	httpntlm	1.8.13
➖	httpreq	1.1.1
➖	is-typedarray	1.0.0
➖	isstream	0.1.2
➖	jose	4.14.4
➖	js-md4	0.3.2
➖	js-sha512	0.9.0
➖	json-schema	0.4.0
➖	jsprim	2.0.2
➖	liquid-json	0.3.1
➖	mime-format	2.0.1
➖	newman	6.2.1
➖	node-forge	1.3.1
		Removed vulnerabilities (2):
➖	node-forge-flash	0.0.0
➖	node-oauth1	1.3.0
➖	oauth-sign	0.9.0
➖	object-hash	1.3.1
➖	parse-ms	2.1.0
➖	performance-now	2.1.0
➖	postman-collection	4.4.0
➖	postman-collection-transformer	4.1.8
➖	postman-request	2.88.1-postman.34
➖	postman-runtime	7.39.1
➖	postman-sandbox	4.7.1
➖	postman-url-encoder	3.0.5
➖	pretty-ms	7.0.1
➖	process-nextick-args	2.0.1
➖	psl	1.15.0
♾️	qs	6.5.3	6.13.0
➖	serialised-error	1.1.3
➖	sshpk	1.18.0
♾️	stack-trace	0.0.9	0.0.10
➖	stream-length	1.0.2
➖	teleport-javascript	1.0.0
➖	tweetnacl	0.14.5
➖	underscore	1.12.1
➖	uvm	2.1.1
➖	verror	1.10.0
➖	webhook-handler	0.9.0
➖	webhooks2tasks	1.0.0
♾️	xmlbuilder	15.1.1	11.0.1

[shreddedbacon]

I forgot that backup-handler still forwarded messages to the legacy webhooks2tasks which is removed in this PR.
Will need to do some refactoring to the backup-handler to work around this.

Edit: Done