`script::Builder::push_slice` is not beginner friendly.

Pushing a script into a Script is a very common step that we need to do in wrapper segwit. sh(wsh), sh(wpkh). Here is how I had to do it in rust-miniscript.

+use bitcoin::script::{PushBytes, PushBytesBuf};
+use core::convert::TryFrom;
 use bitcoin::{script, Address, Network, ScriptBuf};
 
 
-                script::Builder::new()
-                    .push_script(&witness_script.to_v0_p2wsh())
-                    .into_script()
+                let push_bytes = PushBytesBuf::try_from(witness_script.into_bytes())
+                    .expect("Witness script is not too large");
+                script::Builder::new().push_slice(&push_bytes).into_script()
             }
             ShInner::Wpkh(ref wpkh) => {
                 let redeem_script = wpkh.script_pubkey();
-                script::Builder::new()
-                    .push_script(&redeem_script)
-                    .into_script()
+                let push_bytes: &PushBytes =
+                    <&PushBytes>::try_from(redeem_script.as_bytes()).unwrap();
+                script::Builder::new().push_slice(&push_bytes).into_script()

Doing a wintess_script.as_bytes().try_into().unwrap() does not work as rust still requires us to specify the exact that we want to try_into.
multiple impls satisfying _: TryFrom<&[u8]>found in the following crates:bitcoin, core: ...

Importing a new type and reading it's documentation is a nice thing to do, but only to find out that we only fail when the total script size can exceed 2**32 which is exceedingly high. I propose we add the following methods that are more beginner friendly.

// We handle creating the pushbytes internally.
pub fn try_push_slice<S: AsRef<[u8]>>(sl: S) -> Result<Builder, Builder>;

pub fn push_slice_unchecked<S: AsRef<[u8]>>(sl: S) -> Builder;

Does not require the user to understand the inner workings of what pushbytes is and how it actually works. cc @Kixunil

Start with the implementation and documentation for script::Builder::push_slice, PushBytes, and PushBytesBuf, then read the issue discussion before choosing an API. The proposed behavior is to simplify pushing byte slices while preserving oversized-script handling; completion would require an agreed design and tests covering the accepted methods.