feat: add metadata versions endpoints (#1424)

* feat: add metadata versions endpoints

* updated docs

* fix typo & renamed variables

* made the metadata version check dynamic, replacing the specific check for versions 14 and 15
- transaction material with metadata returns metadata regardless of the 'metadata' query param
- updated docs

* added changes from Tarik's review
- throw an error if newer call is not available for older blocks
- removed some comments left in node transaction spec file

* Tarik's change on regExPattern check

Co-authored-by: Tarik Gul <[email protected]>

* added Tarik's suggestion also in transaction material

* fix typo

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Co-authored-by: Tarik Gul <[email protected]>