Go through .unwrap() statements, fail gracefully instead

[brainstorm]

This GlitchOcurred panic can happen anytime there's a transient in serial lines (not often, but the chip should not completely halt).

Go through those and produce an event+fail and continue working gracefully as much as possible.

====================== PANIC ======================
panicked at /Users/rvalls/dev/personal/ssh-stamp/src/espressif/buffered_uart.rs:53:72:
called `Result::unwrap()` on an `Err` value: GlitchOccurred

Backtrace:

0x420401f4
core::result::unwrap_failed
    at /Users/rvalls/.rustup/toolchains/esp/lib/rustlib/src/rust/library/core/src/result.rs:1704
0x4201eb90
core::result::Result<T,E>::unwrap
    at /Users/rvalls/.rustup/toolchains/esp/lib/rustlib/src/rust/library/core/src/result.rs:1109
0x4201d880
embassy_executor::raw::util::SyncUnsafeCell<T>::get
    at /Users/rvalls/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/embassy-executor-0.7.0/src/raw/util.rs:55
0x408008c4
esp_hal::interrupt::riscv::vectored::handle_interrupt
    at /Users/rvalls/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/esp-hal-1.0.0-beta.1/src/interrupt/riscv.rs:513
0x40800258
0x42051596
core::task::wake::Waker::wake_by_ref
    at /Users/rvalls/.rustup/toolchains/esp/lib/rustlib/src/rust/library/core/src/task/wake.rs:465
0x408008c4
esp_hal::interrupt::riscv::vectored::handle_interrupt
    at /Users/rvalls/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/esp-hal-1.0.0-beta.1/src/interrupt/riscv.rs:513
0x40800258
0x4201d72a
embassy_executor::raw::util::SyncUnsafeCell<T>::get
    at /Users/rvalls/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/embassy-executor-0.7.0/src/raw/util.rs:55
0x4203b8c8
main
    at /Users/rvalls/dev/personal/ssh-stamp/src/main.rs:25

[brainstorm]

Still a few more to go, but mostly under control thanks to PRs #66 #68 #70 and #73, thanks @trufae!

$ rg unwrap
src/config.rs
104:        s.push_str(DEFAULT_SSID).unwrap();

src/espressif/buffered_uart.rs
85:                                    .unwrap_or_default();

src/espressif/net.rs
149:        .unwrap_or_else(|_| {

src/main.rs
173:        .unwrap();

ota/src/tlv.rs
118:                    *element = u8::dec(s).unwrap_or(0);

ota/src/bin/ota-packer.rs
86:    reader.seek(SeekFrom::Start(seek_to_bin as u64)).unwrap();
92:        r = reader.read(&mut buffer).unwrap_or(0);
107:        if recovered_firmware_sha256 != &header.sha256_checksum.unwrap_or_default() {
110:                header.sha256_checksum.unwrap_or_default(),
130:        Ok(metadata) => u32::try_from(metadata.len()).unwrap_or_else(|_| {