Add Signers and Signatures fields to txdetail view

[enobayram]

This PR adds the "Signers" and "Signatures" fields to the txdetail view. These new fields display the new TxDetails fields of the chainweb-data API added by kadena-io/chainweb-data#152 and kadena-io/chainweb-data#153.

We used to have this information in the block transactions view before we redesigned that view to be a table of brief information about each transaction, each row linking to the corresponding txdetail page, losing the Signers and Signatures information in the process. This PR recovers these fields for the block-explorer.

[enobayram]

Here are some example transactions with non-trivial "Signer" and "Signers" fields:

I've hidden these screenshots because they got obsoleted by later commits

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http://localhost:8000/mainnet/txdetail/0CLa3cnmJlH0jPspdK1q8EDTKo-qMhRzmBUim5SiwD0

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http://localhost:8000/mainnet/txdetail/-JZxl2e-EkY87WqYSZ07r9cRkQ4It1LQGV2Mgv52cMM

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http://localhost:8000/mainnet/txdetail/Gwgfnn5hbaJgzi15k1up3iwNroqF7s3HfvzdkQqTbSw

[enobayram]

The same screenshots after the latest commits (renaming Account -> Address and removing Address, Scheme if they're empty:

I've hidden these screenshots because they got obsoleted by later commits

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http://localhost:8000/mainnet/txdetail/0CLa3cnmJlH0jPspdK1q8EDTKo-qMhRzmBUim5SiwD0

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http://localhost:8000/mainnet/txdetail/Gwgfnn5hbaJgzi15k1up3iwNroqF7s3HfvzdkQqTbSw

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http://localhost:8000/mainnet/txdetail/-JZxl2e-EkY87WqYSZ07r9cRkQ4It1LQGV2Mgv52cMM

[enobayram]

The same screenshots after applying @emmanueldenloye's suggestion of separating SigCap arguments (also extended to the signatures list)

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http://localhost:8000/mainnet/txdetail/0CLa3cnmJlH0jPspdK1q8EDTKo-qMhRzmBUim5SiwD0

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http://localhost:8000/mainnet/txdetail/Gwgfnn5hbaJgzi15k1up3iwNroqF7s3HfvzdkQqTbSw

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http://localhost:8000/mainnet/txdetail/-JZxl2e-EkY87WqYSZ07r9cRkQ4It1LQGV2Mgv52cMM

[emmanueldenloye]

LGTM