codebase: Remove web frontend and related services (#2067)

* codebase: Remove web frontend and related services

* refactor: Update StartPPROF to accept context and adjust related tests

* refactor: Simplify SetIfZero functions and update related tests

* config: Clarify DowngradeConfig method documentation regarding permanent removal of deprecated fields

* refactor: Rename setIfZeroAndWarn to setDefaultIfZeroWarn for clarity and update related calls

* refactor: Update error handling in DataHistoryManager and remove redundant error variable

testdata/README.md

@@ -25,7 +25,7 @@ It also has the code coverage test files that allow us to monitor our entire
 codebase, click this link for more information [https://codecov.io/](https://codecov.io/).
 ## Donations
 
-<img src="https://github.com/thrasher-corp/gocryptotrader/blob/master/web/src/assets/donate.png?raw=true" hspace="70">
+<img src="/docs/assets/donate.png" hspace="70">
 
 If this framework helped you in any way, or you would like to support the developers working on it, please donate Bitcoin to:
 

testdata/configtest.json

@@ -187,17 +187,6 @@
    "listenAddress": "localhost:9052",
    "grpcProxyEnabled": true,
    "grpcProxyListenAddress": "localhost:9053"
-  },
-  "deprecatedRPC": {
-   "enabled": true,
-   "listenAddress": "localhost:9050"
-  },
-  "websocketRPC": {
-   "enabled": true,
-   "listenAddress": "localhost:9051",
-   "connectionLimit": 1,
-   "maxAuthFailures": 3,
-   "allowInsecureOrigin": true
   }
  },
  "portfolioAddresses": {