This PR implements the Aho-Corasick string matching algorithm under the com.thealgorithms.searches package.

The Aho-Corasick algorithm is a multi-pattern matching algorithm that efficiently finds all occurrences of a set of pattern strings within an input text in a single pass. It is particularly useful when searching for a large dictionary of keywords (e.g., in virus signatures, spam filters, or keyword matching).

Implementation Details
Trie Construction: Inserts all input patterns into a Trie (keyword tree) in $O(m)$ time, where $m$ is the total length of all patterns.
Failure and Output Links: Computes failure transitions and output shortcuts using a Breadth-First Search (BFS) traversal.
A failure link points to the node representing the longest proper suffix of the current prefix that is also a prefix of some pattern.
An output link shortcuts to the next node in the failure chain that represents a complete pattern match, ensuring $O(1)$ lookup per match.
Search Traversal: Scans the input text once in $O(n + z)$ time, where $n$ is the length of the text and $z$ is the number of matched occurrences.
Complexity
Time Complexity: $O(n + m + z)$ where:
$n$ is the length of the input text.
$m$ is the total length of all pattern strings.
$z$ is the number of matches found.
Space Complexity: $O(m)$ to store the Trie state transitions.
Example Behavior
For the input:

Text: ahishers
Patterns: ["he", "she", "his", "hers"]
The output matches:

his at index 1
she at index 3
he at index 4
hers at index 4
Testing
Comprehensive unit tests have been added under com.thealgorithms.searches.AhoCorasickSearchTest covering:

Basic search with overlapping matches (as described above)
Edge cases (null/empty text, null/empty pattern list)
Inputs with no matching patterns
Complex overlapping duplicates (e.g. text "aaaa" with patterns ["a", "aa", "aaa", "aaaa"])