fix: migrate get_dynamic_global_properties from database_api to condenser_api

[ety001]

Problem

get_dynamic_global_properties in hive/steem/http_client.py still maps to database_api, while all other methods in METHOD_API already use condenser_api.

This causes a Bad Cast error when the request reaches steemd, because:

1. _rpc_body() generates params={} for database_api methods (line 78)
2. jussi Go translateToAppbase rewrites database_api.* → condenser_api.* but does not normalize params format
3. steemd appbase requires params=[] (array) for condenser_api methods
4. Result: Bad Cast: Invalid cast from object_type to Array

Fix

Change the METHOD_API mapping:

# Before
get_dynamic_global_properties='database_api',

# After
get_dynamic_global_properties='condenser_api',

_rpc_body() already has the logic to use [] for condenser_api methods (line 78: args = [] if 'condenser_api' in method else {}), so this one-line change fixes both the namespace and the params format.

Context

• database_api is a low-level steemd plugin API being phased out
• condenser_api is the public-facing high-level API that wraps database_api, follow_api, tags_api
• jussi (both Go and Python) already translates all database_api.* calls to condenser_api.* via translateToAppbase
• hivemind only serves condenser_api (asserts api == 'condenser_api' in call.py)
• This was the last remaining database_api usage in hivemind's HTTP client

Testing

Verified against api.steemit.com:

# database_api + object params → Bad Cast ❌
curl -s -X POST https://api.steemit.com \
  -d '{"jsonrpc":"2.0","method":"database_api.get_dynamic_global_properties","params":{},"id":1}' \
  -H 'Content-Type: application/json'

# condenser_api + array params → Success ✅
curl -s -X POST https://api.steemit.com \
  -d '{"jsonrpc":"2.0","method":"condenser_api.get_dynamic_global_properties","params":[],"id":1}' \
  -H 'Content-Type: application/json'