feat: add initializing wallet config

- add config.rs to store and retrieve
values
- add toml and serde crates for desearilizing and
reading values
- update utils, commands and handlers files
to use values from config.toml
-refactor prepare_wallet_db fn
- fix clippy issues

[Issue: #192]

Author: tvpeter

CHANGELOG.md

@@ -4,6 +4,8 @@ Changelog info is also documented on the [GitHub releases](https://github.com/bi
 page. See [DEVELOPMENT_CYCLE.md](DEVELOPMENT_CYCLE.md) for more details.
 
 ## [Unreleased]
+- Add wallet configs initialization for initialiazing and saving wallet configs
+- Add wallet subcommand `config` to save wallet configs
 
 ## [2.0.0]