feat(sdk): with _opts methods

Now all opt values enter into a _opts function instead of the original.
This avoids a lot of verbosity for both None in the case opts are
unwanted, and Some() if they actually are.

They are used like so:

```rust
client.container().from("...");
client.container_opts(Some(ContainerOpts{ ... }))
```

Some from opts will be removed in a future commit/pr

crates/dagger-sdk/examples/build-the-application/main.rs

@@ -3,7 +3,7 @@ use dagger_sdk::HostDirectoryOpts;
 fn main() -> eyre::Result<()> {
     let client = dagger_sdk::connect()?;
 
-    let host_source_dir = client.host().directory(
+    let host_source_dir = client.host().directory_opts(
         "examples/build-the-application/app",
         Some(HostDirectoryOpts {
             exclude: Some(vec!["node_modules".into(), "ci/".into()]),
@@ -12,23 +12,23 @@ fn main() -> eyre::Result<()> {
     );
 
     let source = client
-        .container(None)
+        .container()
         .from("node:16")
         .with_mounted_directory("/src", host_source_dir.id()?);
 
     let runner = source
         .with_workdir("/src")
-        .with_exec(vec!["npm", "install"], None);
+        .with_exec(vec!["npm", "install"]);
 
-    let test = runner.with_exec(vec!["npm", "test", "--", "--watchAll=false"], None);
+    let test = runner.with_exec(vec!["npm", "test", "--", "--watchAll=false"]);
 
     let build_dir = test
-        .with_exec(vec!["npm", "run", "build"], None)
+        .with_exec(vec!["npm", "run", "build"])
         .directory("./build");
 
     let _ = build_dir.export("./build");
 
-    let entries = build_dir.entries(None);
+    let entries = build_dir.entries();
 
     println!("build dir contents: \n {:?}", entries);