Added Ticker Search

[aheschl1]

This pull request includes several changes to the alphavantage project, focusing on adding functionality for retrieving ticker symbols and parsing time formats. The most important changes include the addition of a new module for handling ticker symbols, updates to the client to support ticker symbol searches, and new parsing functions for time formats.

New functionality:

• src/tickers.rs: Added a new module to handle ticker symbol searches, including the SearchResults and Entry structs, and the parser module for parsing search results.

Client updates:

• src/client.rs: Updated the client to include a new method get_tickers for retrieving ticker symbols that match a specified query.
• src/client.rs: Modified imports to include the new tickers module.

Parsing improvements:

• src/deserialize.rs: Added a new constant TIME_FORMAT and a function parse_time to handle time parsing. [1] [2]

Configuration updates:

• Cargo.toml: Updated the package version from 0.7.0 to 0.7.1.

Test additions:

• tests/json/ticker_search_tesco.json, tests/json/ticker_search_tencent.json: Added new JSON test files for ticker symbol search results. [1] [2]

[asmarques]

Looks good. The only thing I would add is an implementation of get_tickers in blocking.rs to maintain feature parity between sync and async clients.

[aheschl1]

Added it to blocking.rs in new a commit

[asmarques]

Thanks, I have now published v0.7.1 with these changes.