TXS: Improve transactions so that they all use correct `prepare` and `execute` syntax

[joshuahannan]

Issue To Be Solved

It is a best practice in cadence to only perform actions that are associated with the transaction signer's account in the prepare phase of a transaction, and perform all external interaction in the execute phase.

Suggest A Solution

• Update the sample transactions in transactions/ to use both phases.

Example: transactions/admin/add_plays_to_set.cdc would be changed from:

transaction(setID: UInt32, plays: [UInt32]) {

    prepare(acct: AuthAccount) {

        // borrow a reference to the Admin resource in storage
        let admin = acct.borrow<&TopShot.Admin>(from: /storage/TopShotAdmin)
            ?? panic("Cannot borrow a reference to the admin resource")

        // borrow a reference to the set to be added to
        let setRef = admin.borrowSet(setID: setID)

        // Add the specified play IDs
        setRef.addPlays(playIDs: plays)
    }
}

to:

import TopShot from 0xTOPSHOTADDRESS

// This transaction adds multiple plays to a set
		
transaction(setID: UInt32, plays: [UInt32]) {

    // Local variable for the topshot Admin object
    let adminRef: &TopShot.Admin

    prepare(acct: AuthAccount) {

        // borrow a reference to the Admin resource in storage
        self.adminRef = acct.borrow<&TopShot.Admin>(from: /storage/TopShotAdmin)!
    }

    execute() {

        // borrow a reference to the set to be added to
        let setRef = self.adminRef.borrowSet(setID: setID)

        // Add the specified play IDs
        setRef.addPlays(playIDs: plays)
    }
}