Add DNS provider for Technitium

[ldez]

• adds a description to your PR
• have a homogeneous design with the other providers
• add tests (units)
• add tests ("live")
• add a provider descriptor
• generate CLI help, documentation, and readme.
• be able to do: (and put the output of this command to a comment)

  make build
  rm -rf .lego
  
  TECHNITIUM_SERVER_BASE_URL="http://localhost:5380" \
  TECHNITIUM_API_TOKEN="xxxxxxxxxxxxxxxxxxxxx" \
  ./dist/lego --email you@example.com --dns technitium -d '*.example.com' -d example.com -s https://acme-staging-v02.api.letsencrypt.org/directory run

  Note the wildcard domain is important.
• pass the linter
• do go mod tidy

Ping @abdeldjalil-fellah, can you run the command (with your domain, email, credentials, etc.)?

Closes #2331

How to test this PR?

1. You need Go
2. Checkout the PR:

   git clone https://github.com/ldez/lego.git
   cd lego
   git checkout feat/technitium

3. Compile lego:
   • if you have make: make build
   • if you don't make make: go build ./cmd/lego -o dist/lego
4. Run the following command with your information (email, domain, credentials, etc.):

   TECHNITIUM_SERVER_BASE_URL="http://localhost:5380" \
   TECHNITIUM_API_TOKEN="xxxxxxxxxxxxxxxxxxxxx" \
   ./dist/lego --email you@example.com --dns technitium -d '*.example.com' -d example.com -s https://acme-staging-v02.api.letsencrypt.org/directory run

   The wildcard domain is important
5. Before each run of the command, you should clean your local environment:

   rm -rf .lego

Related to #2331 (reply in thread)

[ldez]

Maybe @ShreyasZare will want to try the PR.

[abdeldjalil-fellah]

It works! tested on local machine with pebble:

local machine (technitium-dnsserver): 192.168.43.215
pebble machine: 192.168.43.201
note: the ca.pem that generates cert.pem should be added to system trust store

[dmke]

Just a small typo, otherwise LGTM