Small improvements on the mining page UX

- INDEXING_BLOCKS_AMOUNT = 0 disable indexing, INDEXING_BLOCKS_AMOUNT = -1 indexes everything
- Show only available timespan in the mining page according to available datas
- Change default INDEXING_BLOCKS_AMOUNT to 1100

Don't use unfiltered mysql user input

Enable http cache header for mining pools (1 min)

backend/src/index.ts

@@ -255,7 +255,7 @@ class Server {
         .get(config.MEMPOOL.API_URL_PREFIX + 'statistics/1y', routes.$getStatisticsByTime.bind(routes, '1y'))
         .get(config.MEMPOOL.API_URL_PREFIX + 'statistics/2y', routes.$getStatisticsByTime.bind(routes, '2y'))
         .get(config.MEMPOOL.API_URL_PREFIX + 'statistics/3y', routes.$getStatisticsByTime.bind(routes, '3y'))
-        .get(config.MEMPOOL.API_URL_PREFIX + 'pools', routes.$getPools)
+        .get(config.MEMPOOL.API_URL_PREFIX + 'mining/pools', routes.$getPools)
         ;
     }