Filtering of synchronized secrets on collection, organization, and/or folder (#12)

* Filtering feature, minor logic changes
+: Add IP validation (to properly log IP even when trusted proxy is missing)
+: Added synchronization of decrypted organization, collection, and folder names (for filtering purposes)
+: Changed sync behavior to prevent collapsing multiple logins with the same name
+: Added possibility to filter logins based on organization, collection, and folder name/id in GetSecret
+: Added support for space character in secret name validation (it is also properly URL-decoded)

* Update README

* Fixes related to issues reported by CodeRabbit:
+: Changed british use of organisations in README
+: Reduced line count in parseSecretFilters by including helper function for filter dimensions resolution
+: Added comment clarifying absence of existence checking on dimension IDs as opposed to names
+: Removed efensive comma split logic on IPs (redundant due to IPValidation setting on Fiber)
+: Changed Query validator to align with name validator (mainly removing hard-coded values)
+: Added comments to decryptVaultLabel for clarity
+: Change empty SyncNameMaps instance with emptySyncNameMaps helper for consistency
+: Add lexical sort for lookupIDByName for deterministic result in case of multiple matches

* Bumped logging to warn and added entity metadata in log

* Unit tests:
+: Added unit tests for every newly introduced or changed function
+: Rewrote NewClient constructor to accept optional preloaded data (so it can be used in test scenarios)

* Changes requested by CodeRabbit

internal/validators/validators_test.go

@@ -0,0 +1,42 @@
+package validators
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestIsValidFilterQueryValue(t *testing.T) {
+	t.Parallel()
+
+	// Test allowed length of filter query values
+	longOK := strings.Repeat("a", SecretNameMaxLength)
+	tooLong := strings.Repeat("a", SecretNameMaxLength+1)
+
+	tests := []struct {
+		name  string
+		input string
+		want  bool
+	}{
+		// Add test cases here
+		{"simple name", "Acme Corp", true},
+		{"trimmed valid", "  Dev Team  ", true},
+		{"unicode printable", "Team-α", true},
+		{"max length", longOK, true},
+		{"empty", "", false},
+		{"whitespace only", "   ", false},
+		{"too long", tooLong, false},
+		{"newline", "bad\nname", false},
+		{"tab", "bad\tname", false},
+		{"del control", "bad\x7fname", false},
+		{"null", "bad\x00name", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := IsValidFilterQueryValue(tt.input); got != tt.want {
+				t.Errorf("IsValidFilterQueryValue(%q) = %v, want %v", tt.input, got, tt.want)
+			}
+		})
+	}
+}