Taskwarrior doesn't support `\uXXXX` sequences in tags when reading from hooks

When interacting with hooks, taskwarrior doesn't handle escape sequences in `tags` field.

But escape sequences are supported in `description` field. So I think this is a bug.

+ What command(s) did you run?

I was using a simplified hook script from [timewarrior](https://github.com/GothenburgBitFactory/timewarrior):

```python3
#!/usr/bin/python3

import json
import sys

lineold = sys.stdin.buffer.readline().decode("utf-8", errors="replace")
linenew = sys.stdin.buffer.readline().decode("utf-8", errors="replace")
new = json.loads(linenew)
print(json.dumps(new))
```

and ran these command below:

```sh
task add tags:🤔🤔🤔🤔 😋😋😋😋
task 1 start
task
```

+ What did you expect to happen?

I expect the tags remain readable:

+ What actually happened?

I got this:

+ Paste the output of the task diag command.

```plain
task 2.6.1
Platform: Linux

Compiler
Version: 11.2.0
Caps: +stdc +stdc_hosted +LP64 +c8 +i32 +l64 +vp64 +time_t64
Compliance: C++17

Build Features
Commit: e60fdafda
CMake: 3.22.1
libuuid: libuuid + uuid_unparse_lower
libgnutls: n/a
Build type:

Configuration
File: /home/jyi/.taskrc (found), 1562 bytes, mode 100644
Data: /home/jyi/.task (found), dir, mode 40755
Locking: Enabled
GC: Enabled
$EDITOR: vim
Server:
CA: -
Certificate: -
Key: -
Trust: strict
Ciphers: NORMAL
Creds:

Hooks
System: Enabled
Location: /home/jyi/.task/hooks
Active: on-modify.timewarrior (executable)
Inactive:

Tests
Terminal: 120x30
Dups: Scanned 20 tasks for duplicate UUIDs:
No duplicates found
Broken ref: Scanned 20 tasks for broken references:
No broken references found
```

I tried to add some print statement in the hook script, like:

```python3
#!/usr/bin/python3

import json
import sys

lineold = sys.stdin.buffer.readline().decode("utf-8", errors="replace")
linenew = sys.stdin.buffer.readline().decode("utf-8", errors="replace")
print("raw =", linenew, file=sys.stderr)
new = json.loads(linenew)
print(json.dumps(new))
print("dump =", json.dumps(new), file=sys.stderr)
```

and then run

```sh
task add tags:🤔🤔🤔🤔 😋😋😋😋
task 1 start
cat ~/.task/pending.data
```

then I got this output:

```plain
Created task 1.
raw = {"description":"😋😋😋😋","entry":"20220309T024947Z","modified":"20220309T024947Z","start":"20220309T024947Z","status":"pending","uuid":"74adece9-dc11-4efd-9b51-e161d8670ba3","tags":["🤔🤔🤔🤔"]}

dump = {"description": "\ud83d\ude0b\ud83d\ude0b\ud83d\ude0b\ud83d\ude0b", "entry": "20220309T024947Z", "modified": "20220309T024947Z", "start": "20220309T024947Z", "status": "pending", "uuid": "74adece9-dc11-4efd-9b51-e161d8670ba3", "tags": ["\ud83e\udd14\ud83e\udd14\ud83e\udd14\ud83e\udd14"]}
Starting task 74adece9 '����������������'.
Started 1 task.
[description:"����������������" entry:"1646794187" modified:"1646794187" start:"1646794187" status:"pending" tags:"\\ud83e\\udd14\\ud83e\\udd14\\ud83e\\udd14\\ud83e\\udd14" tags_\ud83e\udd14\ud83e\udd14\ud83e\udd14\ud83e\udd14:"x" uuid:"74adece9-dc11-4efd-9b51-e161d8670ba3"]
```

It seems that the script printed tags with `\uXXXX` escape sequence, and taskwarrior didn't unescape these sequences but have them escaped again. And then the tag became unreadable.

I guess that support escape sequences in tags may solve this problem.

Thaks in advance for your help.

Reproduce the issue with the on-modify.timewarrior hook and the task add/start commands shown, then inspect how hook JSON is read and written before the data reaches ~/.task/pending.data. Done means Unicode tags remain readable after the hook round trip, matching the behavior already observed for descriptions.

Written by the indexing model from the issue text.