refactor(config)!: Use clap derive API and figment for config parsing

Use figment for parsing configuration from env vars, cli, toml file.

Switch from clap builder api to clap derive api. This creates a struct
that then be fed to figment.

Remove old homegrown config builder.

Remove direct toml dependency, it's handled by figment now.

Update documentation concerning booleanss and numbers.

BREAKING CHANGE: toml booleans and numbers in the config files
can't be quoted anymore. Previously they had to be quoted strings due
to implementation issues.

config/do_ddns.sample.toml

@@ -7,16 +7,16 @@ update_interval = "30mins"
 digital_ocean_token = "aabbccddeeffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz"
 
 # Setting this option to true will cause the final IP updates to be skipped.
-dry_run = "false"
+dry_run = false
 
 # Setting this option to true will enable resolving of ipv6 addresses and 
 # storing them in AAAA records.
-# ipv6 = "true"
+# ipv6 = true
 
 # Enable collection of statistics (how often does the public IP change) in
 # a local sqlite database.
 # Disabled by default.
-# collect_stats = "true"
+# collect_stats = true
 
 # File path where the sqlite database with statistics will be stored.
 # By default stored in one of the following locations:
@@ -26,16 +26,16 @@ dry_run = "false"
 
 # Enable web server to visualize collected statistics.
 # Disabled by default.
-# enable_web = "true"
+# enable_web = true
 
 # An IPv4 / IPv6 address or host name where to serve HTTP pages on.
 # In case of host that has a dual IP stack, both will be used.
 # Default is localhost.
-# listen_hostname = "true"
+# listen_hostname = true
 
 # Port number where to serve HTTP pages on.
 # Default is 8095.
-# listen_port = "8095"
+# listen_port = 8095
 
 ## Simple config mode sample
 
@@ -48,7 +48,7 @@ subdomain_to_update = "home"
 
 # Updates the IP of the 'mysite.com' A record.
 # domain_root = "mysite.com"
-# update_domain_root = "true"
+# update_domain_root = true
 
 
 ## Advanced config mode sample

crates/dyndns/Cargo.toml

@@ -56,7 +56,6 @@ serde_json = "1"
 serde_with = "3"
 signal-hook = { version = "0.3", features = ["extended-siginfo"] }
 tailsome = "1"
-toml = "0.7"
 tracing = "0.1"
 tracing-log = "0.1"
 tracing-subscriber = "0.3"