[reconfigurator] ClickHouse XML generation types (#6412)

## Overview

This commit adds a library to generate ClickHouse replica server and
keeper configuration files. A lot of the code in the
`clickhouse-admin/types` directory has been copied over from
[clickward](https://github.com/oxidecomputer/clickward), but there are
several additions and modifications:

- New `new()` and `default()` methods that set default Oxide values.
- File generation is per node, as opposed to all files generated in a
single directory like clickward.

## Usage

To generate a replica server configuration file:

```rust
let keepers = vec![
    KeeperNodeConfig::new("ff::01".to_string()),
    KeeperNodeConfig::new("ff::02".to_string()),
    KeeperNodeConfig::new("ff::03".to_string()),
];

let servers = vec![
    ServerNodeConfig::new("ff::08".to_string()),
    ServerNodeConfig::new("ff::09".to_string()),
];

let config = ClickhouseServerConfig::new(
    Utf8PathBuf::from(config_dir.path()),
    ServerId(1),
    Utf8PathBuf::from_str("./").unwrap(),
    Ipv6Addr::from_str("ff::08").unwrap(),
    keepers,
    servers,
);

config.generate_xml_file().unwrap();
```

To generate a keeper configuration file:

```rust
let keepers = vec![
    RaftServerConfig::new(KeeperId(1), "ff::01".to_string()),
    RaftServerConfig::new(KeeperId(2), "ff::02".to_string()),
    RaftServerConfig::new(KeeperId(3), "ff::03".to_string()),
];

let config = ClickhouseKeeperConfig::new(
    Utf8PathBuf::from(config_dir.path()),
    KeeperId(1),
    keepers,
    Utf8PathBuf::from_str("./").unwrap(),
    Ipv6Addr::from_str("ff::08").unwrap(),
);

config.generate_xml_file().unwrap();
```

## Purpose

As part of the work to roll out replicated ClickHouse, we'll need to
dynamically generate the node configuration files via the
`clickhouse-admin` service. This commit is part of the work necessary to
do so.

Related: #5999 ,
#3824

Cargo.toml

@@ -122,6 +122,7 @@ default-members = [
     "certificates",
     "clickhouse-admin",
     "clickhouse-admin/api",
+    "clickhouse-admin/types",
     "clients/bootstrap-agent-client",
     "clients/cockroach-admin-client",
     "clients/ddm-admin-client",
@@ -311,6 +312,7 @@ chrono = { version = "0.4", features = [ "serde" ] }
 ciborium = "0.2.2"
 clap = { version = "4.5", features = ["cargo", "derive", "env", "wrap_help"] }
 clickhouse-admin-api = { path = "clickhouse-admin/api" }
+clickhouse-admin-types = { path = "clickhouse-admin/types" }
 clickward = { git = "https://github.com/oxidecomputer/clickward", rev = "ceec762e6a87d2a22bf56792a3025e145caa095e" }
 cockroach-admin-api = { path = "cockroach-admin/api" }
 cockroach-admin-client = { path = "clients/cockroach-admin-client" }

clickhouse-admin/Cargo.toml

@@ -10,6 +10,7 @@ camino.workspace = true
 chrono.workspace = true
 clap.workspace = true
 clickhouse-admin-api.workspace = true
+clickhouse-admin-types.workspace = true
 dropshot.workspace = true
 http.workspace = true
 illumos-utils.workspace = true

clickhouse-admin/types/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "clickhouse-admin-types"
+version = "0.1.0"
+edition = "2021"
+license = "MPL-2.0"
+
+[lints]
+workspace = true
+
+[dependencies]
+anyhow.workspace = true
+camino.workspace = true
+camino-tempfile.workspace = true
+derive_more.workspace = true
+omicron-common.workspace = true
+omicron-workspace-hack.workspace = true
+schemars.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+expectorate.workspace = true