put delegations into escrow account metadata

[pro-wh]

for #61

This takes an unsophisticated approach. Load the delegations and debonding delegations from the existing staking API and put them into the metadata area under new keys. The format that they're in is fine as is.

Also add info about the breakdown of the escrow balance into active and debonding pools and info about the shares.

A preview, where the test entity has delegated 2,000 base units to the testing destination account:

The test entity's (oasis1qzzd6khm3acqskpxlk9vd5044cmmcce78y5l6000) escrow account

{
    "block_identifier": {
        "index": 175, 
        "hash": "8472f4494618356dcfa346a52c1f15f90277470409977018b4f11134c0908715"
    }, 
    "balances": [
        {
            "value": "100000000000", 
            "currency": {
                "symbol": "ROSE", 
                "decimals": 9
            }
        }
    ], 
    "metadata": {
        "active_balance": "100000000000", 
        "active_shares": "1", 
        "debonding_balance": "0", 
        "debonding_delegations": { }, 
        "debonding_shares": "0", 
        "delegations": {
            "oasis1qpkant39yhx59sagnzpc8v0sg8aerwa3jyqde3ge": {
                "shares": "2000"
            }, 
            "oasis1qzzd6khm3acqskpxlk9vd5044cmmcce78y5l6000": {
                "shares": "1"
            }
        }, 
        "nonce": 2
    }
}

The testing destination (oasis1qpkant39yhx59sagnzpc8v0sg8aerwa3jyqde3ge) escrow account

{
    "block_identifier": {
        "index": 175, 
        "hash": "8472f4494618356dcfa346a52c1f15f90277470409977018b4f11134c0908715"
    }, 
    "balances": [
        {
            "value": "2000", 
            "currency": {
                "symbol": "ROSE", 
                "decimals": 9
            }
        }
    ], 
    "metadata": {
        "active_balance": "2000", 
        "active_shares": "2000", 
        "debonding_balance": "0", 
        "debonding_delegations": { }, 
        "debonding_shares": "0", 
        "delegations": { }, 
        "nonce": 0
    }
}