feat!: add support for http provider using SAS_SUBSTRATE_URL (#1001)

* docs: update README with SAS_SUBSTRATE_HTTP_URL env var

* add HTTP_URL key

* add HTTP_URL spec

* add HTTP_URL to the types

* feat: add http logic to provider and logging

* lint

* fix grumble

* Update README.md

Co-authored-by: Alexandru Vasile <[email protected]>

* BREAKING CHANGE: switch SAS_SUBSTRATE_WS_URL to SAS_SUBSTRATE_URL

* fix params for startUpPrompt

* Update src/Specs.ts

Co-authored-by: Sergejs Kostjucenko <[email protected]>

* add https to regex

* fix inline comment grumble

Co-authored-by: Alexandru Vasile <[email protected]>
Co-authored-by: Sergejs Kostjucenko <[email protected]>