Fix `--delete-it-all` and `--delete` commands (#913)

* Add `delete_at` is null condition during search

Since entries are searched everytime a delete process ends, the
--delete-it-all command will enter an infinite loop if searching the
whole history.

* Remove command blanking

Command blanking may violate the `unique(timestamp, cwd, command)`
condition.

* Overwrite command with random string when deleting

* Add rand dependency to client crate

---------

Co-authored-by: Ellie Huxtable <ellie@elliehuxtable.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 7a310c01..c3604b68 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -151,6 +151,7 @@ dependencies = [
  "memchr",
  "minspan",
  "parse_duration",
+ "rand",
  "regex",
  "reqwest",
  "rmp-serde",