Fix various typos (#43073)

Fix various typos (#43073)

* Fix various typos
* `occurence`, `occurance` -> `occurrence`
* `accross` -> `across`
* `adddress`, `addresss` -> `address`
* `alignement`, `aligment` -> `alignment`
* Remove `c` from triple c.
* Remove `s` from triple s.
  * In palsuite, `Successs` (with triple s) was in commented out
    `Trace()` message, removed all commented out `Trace()` calls
    from such files.
* Fix invalid markdown in `unix-test-instructions.md`.

* Revert event source change