message: [Doc] Document changes to getstakingstatus output
diff: @@ -88,6 +88,7 @@ RPC Changes
  - "CoinStake" JSON object in `getblock` output is removed, and replaced with the strings "stakeModifier" and "hashProofOfStake"
  +
  - "isPublicSpend" boolean (optional) input parameter is removed from the following commands:
  - `createrawzerocoinspend`
  - `spendzerocoin`
  @@ -96,16 +97,39 @@ RPC Changes
  These commands are now able to create only *public* spends (private spends were already enabled only on regtest).
  +
  - "mintchange" and "minimizechange" boolean input parameters are removed from the following commands:
  - `spendzerocoin`
  Mints are disabled, therefore it is no longer possible to mint the change of a zerocoin spend. The change is minimized by default.
  +
  - `setstakesplitthreshold` now accepts decimal amounts. If the provided value is `0`, split staking gets disabled. `getstakesplitthreshold` returns a double.
  - `dumpwallet` no longer allows overwriting files. This is a security measure
  as well as prevents dangerous user mistakes.
  +- The output of `getstakingstatus` was reworked. It now shows the following information:
  + ```
  + {
  + "staking_status": true|false, (boolean) whether the wallet is staking or not
  + "staking_enabled": true|false, (boolean) whether staking is enabled/disabled in pivx.conf
  + "coldstaking_enabled": true|false, (boolean) whether cold-staking is enabled/disabled in pivx.conf
  + "haveconnections": true|false, (boolean) whether network connections are present
  + "mnsync": true|false, (boolean) whether masternode data is synced
  + "walletunlocked": true|false, (boolean) whether the wallet is unlocked
  + "stakeablecoins": n, (numeric) number of stakeable UTXOs
  + "stakingbalance": d, (numeric) PIV value of the stakeable coins (minus reserve balance, if any)
  + "stakesplitthreshold": d, (numeric) value of the current threshold for stake split
  + "lastattempt_age": n, (numeric) seconds since last stake attempt
  + "lastattempt_depth": n, (numeric) depth of the block on top of which the last stake attempt was made
  + "lastattempt_hash": xxx, (hex string) hash of the block on top of which the last stake attempt was made
  + "lastattempt_coins": n, (numeric) number of stakeable coins available during last stake attempt
  + "lastattempt_tries": n, (numeric) number of stakeable coins checked during last stake attempt
  + }
  + ```
  +
  +
  ### Removed commands
  The following commands have been removed from the RPC interface:
  