* Remove `estimatedGas` property from `txMeta`
The `estimatedGas` property was a cache of the gas value estimated for
a transaction when the default gas limit was set. This property wasn't
used anywhere. It may have been useful for debugging purposes, but the
same gas estimate is already stored on the `history` property so it
should be present in state logs regardless.
* Remove `gasLimitSpecified` txMeta property
The `gasLimitSpecified` property of `txMeta` wasn't used for anything.
It might have been useful for debugging purposes, but whether or not
the gas limit was specified can also be determined from looking at the
transaction history, so it's not a huge loss.
* Remove `gasPriceSpecified` txMeta property
The `gasPriceSpecified` property of `txMeta` wasn't used for anything.
It might have been useful for debugging purposes, but whether or not
the gas price was specified can also be determined from looking at the
transaction history, so it's not a huge loss.
* Remove `simpleSend` txMeta property
The `simpleSend` property of `txMeta` was used to ensure a buffer was
not added to the gas limit during gas estimation for simple send
transactions. It was made redundant by #8484, which accomplishes this
without the use of this property.
