Split scarb-execute into subfiles (#1924)

## Stack
- #1924
- #1900
- #1922 

To expose args and `main_inner` so these are usable by scarb-prove

extensions/scarb-execute/src/args.rs

@@ -0,0 +1,104 @@
+use anyhow::{Context, Result};
+use cairo_lang_runner::Arg;
+use cairo_lang_utils::bigint::BigUintAsHex;
+use camino::Utf8PathBuf;
+use clap::{arg, Parser, ValueEnum};
+use num_bigint::BigInt;
+use scarb_ui::args::{PackagesFilter, VerbositySpec};
+use std::fs;
+
+/// Compiles a Cairo project and runs a function marked `#[executable]`.
+/// Exits with 1 if the compilation or run fails, otherwise 0.
+#[derive(Parser, Clone, Debug)]
+#[clap(version, verbatim_doc_comment)]
+pub struct Args {
+    /// Name of the package.
+    #[command(flatten)]
+    pub packages_filter: PackagesFilter,
+
+    /// Do not rebuild the package.
+    #[arg(long, default_value_t = false)]
+    pub no_build: bool,
+
+    #[clap(flatten)]
+    pub run: ExecutionArgs,
+
+    /// Logging verbosity.
+    #[command(flatten)]
+    pub verbose: VerbositySpec,
+}
+
+#[derive(Parser, Clone, Debug)]
+pub struct ExecutionArgs {
+    #[command(flatten)]
+    pub arguments: ProgramArguments,
+
+    /// Desired execution output, either default Standard or CairoPie
+    #[arg(long, default_value = "standard")]
+    pub output: OutputFormat,
+
+    /// Execution target.
+    #[arg(long, default_value = "standalone")]
+    pub target: ExecutionTarget,
+
+    /// Whether to print the program outputs.
+    #[arg(long, default_value_t = false)]
+    pub print_program_output: bool,
+}
+
+#[derive(Parser, Debug, Clone)]
+pub struct ProgramArguments {
+    /// Serialized arguments to the executable function.
+    #[arg(long, value_delimiter = ',')]
+    pub arguments: Vec<BigInt>,
+
+    /// Serialized arguments to the executable function from a file.
+    #[arg(long, conflicts_with = "arguments")]
+    pub arguments_file: Option<Utf8PathBuf>,
+}
+
+impl ProgramArguments {
+    pub fn read_arguments(self) -> Result<Vec<Arg>> {
+        if let Some(path) = self.arguments_file {
+            let file = fs::File::open(&path).with_context(|| "reading arguments file failed")?;
+            let as_vec: Vec<BigUintAsHex> = serde_json::from_reader(file)
+                .with_context(|| "deserializing arguments file failed")?;
+            Ok(as_vec
+                .into_iter()
+                .map(|v| Arg::Value(v.value.into()))
+                .collect())
+        } else {
+            Ok(self
+                .arguments
+                .iter()
+                .map(|v| Arg::Value(v.into()))
+                .collect())
+        }
+    }
+}
+
+#[derive(ValueEnum, Clone, Debug)]
+pub enum OutputFormat {
+    CairoPie,
+    Standard,
+}
+impl OutputFormat {
+    pub fn is_standard(&self) -> bool {
+        matches!(self, OutputFormat::Standard)
+    }
+    pub fn is_cairo_pie(&self) -> bool {
+        matches!(self, OutputFormat::CairoPie)
+    }
+}
+
+#[derive(ValueEnum, Clone, Debug)]
+pub enum ExecutionTarget {
+    Bootloader,
+    Standalone,
+}
+
+impl ExecutionTarget {
+    pub fn is_standalone(&self) -> bool {
+        matches!(self, ExecutionTarget::Standalone)
+    }
+}