feat: add Shelley protocol parameters support

[verbotenj]

Test

make
./gouroboros -address backbone.cardano-mainnet.iohk.io:3001 -network mainnet -ntn chain-sync -bulk -start-era shelley
...
era = Shelley, slot = 16588702, block_no = 5086521, id = 2772d6484501a4183f3c2376536234c0a27e1da1ed282f9fd1b32890605ee241
era = Shelley, slot = 16588719, block_no = 5086522, id = 7fdf13dc47bc43fe921da6a9bff4ff1c95f2a257a93e1a4c58c13ef7df461545
era = Shelley, slot = 16588737, block_no = 5086523, id = 4e9bbbb67e3ae262133d94c3da5bffce7b1127fc436e7433b87668dba34c354a
era = Allegra, slot = 16588800, block_no = 5086524, id = 078d102d0247463f91eef69fc77f3fbbf120f3118e68cd5e6a493c15446dbf8c

Closes #324

[agaffney]

Please add a ShelleyProtocolParameters type (the equivalent of BabbageProtocolParameters) and wire it up in local-state-query. This should really just be copying ShelleyProtocolParameterUpdate, adding cbor.StructAsArray at the top, removing all of the field annotations, and making the protocol major/minor top-level fields.

[agaffney]

Use an embedded struct to capture the major/minor protocol version in named fields like we did for the Babbage protocol parameters:

	ProtocolVersion    struct {
		cbor.StructAsArray
		Major uint
		Minor uint
	} `cbor:"14,keyasint"`

[agaffney]

Get rid of the doubled D at the beginning of this field name

[agaffney]

Comments above

[agaffney]

This would instead be two top level fields for major/minor like we have for Babbage...for reasons