Few stdlib supports request

[TomChv]

Hey,

While I was working on the Rust SDK dev as part of dagger/dagger#11373, I got stuck on converting it to dang because it requires the following libraries:

import (
	"context"
	"fmt"
	"regexp"
	"strings"

	"github.com/BurntSushi/toml"
	"golang.org/x/mod/semver"

	"dagger/rust-sdk-dev/internal/dagger"
)

That file is the go version of the rust sdk dev.
Once all the listed library are implemented I should be able to convert it to dang.

Tasks

List of stdlib that could be implemented (including the one required for the Rust SDK)

• strings (HasPrefix, Contains...)
• semver
• regexp
• toml
• json (not required but its like toml so why not?)
• yaml (not required but its like toml so why not?)