spec: update light client verification to match supervisor (#171)
* VDD renaming of verification spec + links fixed
* latest()
* backwards
* added TODOs
* link in old file to new name
* better text
* revision done. needs one more round of reading
* renamed constants in 001 according to TLA+ and impl
* ready for PR
* forgot linting
* Update rust-spec/lightclient/verification/verification_002_draft.md
* Update rust-spec/lightclient/verification/verification_002_draft.md
* added lightstore function needed for supervisor
* added lightstore functions for supervisor
* ident
* Update rust-spec/lightclient/verification/verification_002_draft.md
[LCV-DIST-SAFE.1](https://github.com/informalsystems/tendermint-rs/blob/master/docs/spec/lightclient/verification/verification_001_published.md#lcv-dist-safe1) and