Add function to create an instance at a given address

- `assume_safe`: Parse an instance from a given address.
- `assume_safe_with`: Initialize an instance at a given address.

Signed-off-by: Sangwan Kwon <[email protected]>

Safety Enhancements of Unsafe Rust

tools: Add unsafe analyzer `cargo gegier`

Signed-off-by: Sangwan Kwon <[email protected]>

doc: Fix typos and misleading sentences

Some of typos were found with `aspell`.

doc: Update getting started content

Signed-off-by: Sangwan Kwon <[email protected]>

update gui-related stuff

- replace 'netcat' with a simple socket server program
- update README.md to test with browser-based GUIs

Signed-off-by: Jinbum Park <[email protected]>

sdk: Add islet_status_t to handle error

Signed-off-by: Sangwan Kwon <[email protected]>

encode ABI version considering both major and minor

Signed-off-by: Jinbum Park <[email protected]>

update scripts to launch FVP with confidential-ml example

Signed-off-by: Jinbum Park <[email protected]>