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)

frontend/src/app/services/api.service.ts

@@ -121,8 +121,11 @@ export class ApiService {
     return this.httpClient.post<any>(this.apiBaseUrl + this.apiBasePath + '/api/tx', hexPayload, { responseType: 'text' as 'json'});
   }
 
-  listPools$(interval: string) : Observable<PoolsStats> {
-    const params = new HttpParams().set('interval', interval);
-    return this.httpClient.get<PoolsStats>(this.apiBaseUrl + this.apiBasePath + '/api/v1/pools', {params});
+  listPools$(interval: string | null) : Observable<PoolsStats> {
+    let params = {};
+    if (interval) {
+      params = new HttpParams().set('interval', interval);
+    }
+    return this.httpClient.get<PoolsStats>(this.apiBaseUrl + this.apiBasePath + '/api/v1/mining/pools', {params});
   }
 }