Add RandomGenerator to Sui Framework (#15019)

## Description 

Add interfaces for fetching randomness: `RandomGenerator` is a PRG with
a seed that is derived from the global randomness (which is the same
between randomness rounds) and a fresh UID (which is guaranteed to be
unique by the framework). In other words, the seed is unpredictable
without knowing the global randomness, and different for each created
generator (thus not predictable even by different functions invoked for
the same tx).

`RandomGenerator` manages an internal state with a buffer of random
bytes derived using the PRG, and provides high level functions for
deriving integers from those random bytes.

## Test Plan 

Unit tests

---
If your changes are not user-facing and not a breaking change, you can
skip the following section. Otherwise, please indicate what changed, and
then add to the Release Notes section as highlighted during the release
process.

### Type of Change (Check all that apply)

- [x] protocol change
- [ ] user-visible impact
- [ ] breaking change for a client SDKs
- [x] breaking change for FNs (FN binary must upgrade)
- [x] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes
Add Move interfaces for generating secure random values.

crates/sui-framework/docs/sui-framework/hmac.md

@@ -21,7 +21,7 @@ title: Module `0x2::hmac`
 Returns the 32 bytes digest of HMAC-SHA3-256(key, msg).
 
 
-<pre><code><b>public</b> <b>fun</b> <a href="hmac.md#0x2_hmac_hmac_sha3_256">hmac_sha3_256</a>(key: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;, msg: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;): <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;
+<pre><code><b>public</b> <b>fun</b> <a href="../sui-framework/hmac.md#0x2_hmac_hmac_sha3_256">hmac_sha3_256</a>(key: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;, msg: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;): <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;
 </code></pre>
 
 
@@ -30,7 +30,7 @@ Returns the 32 bytes digest of HMAC-SHA3-256(key, msg).
 <summary>Implementation</summary>
 
 
-<pre><code><b>public</b> <b>native</b> <b>fun</b> <a href="hmac.md#0x2_hmac_hmac_sha3_256">hmac_sha3_256</a>(key: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;, msg: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;): <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;;
+<pre><code><b>public</b> <b>native</b> <b>fun</b> <a href="../sui-framework/hmac.md#0x2_hmac_hmac_sha3_256">hmac_sha3_256</a>(key: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;, msg: &<a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;): <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;u8&gt;;
 </code></pre>