intention: cannot modify intention created with CLI after modification from web UI

#### Overview of the Issue

When trying to modify an intention created with the cli through the web interface, a 500 error is returned and the intention is not able to be modified by the cli.

#### Reproduction Steps

_the following example used the counting and counting-dashboard examples found in the consul tutorial_

1. Create a new intention

```
consul intention create dashboard counting
```
2. Modify the `dashboard => counting` intention in the consul web UI from `allow` to `deny`
3. Attempt to modify the `dashboard => counting` intention from the cli

```
consul intention create -deny -replace dashboard counting
```

### Consul info for both Client and Server

Client info

```
➜ ~ consul info
agent:
check_monitors = 0
check_ttls = 0
checks = 6
services = 6
build:
prerelease =
revision = c976ffd2
version = 1.10.3
consul:
acl = disabled
bootstrap = false
known_datacenters = 1
leader = true
leader_addr = 127.0.0.1:8300
server = true
raft:
applied_index = 154
commit_index = 154
fsm_pending = 0
last_contact = 0
last_log_index = 154
last_log_term = 2
last_snapshot_index = 0
last_snapshot_term = 0
latest_configuration = [{Suffrage:Voter ID:3b257ac5-76f6-f00c-9926-fb996cfdf86a Address:127.0.0.1:8300}]
latest_configuration_index = 0
num_peers = 0
protocol_version = 3
protocol_version_max = 3
protocol_version_min = 0
snapshot_version_max = 1
snapshot_version_min = 0
state = Leader
term = 2
runtime:
arch = amd64
cpu_count = 16
goroutines = 164
max_procs = 16
os = darwin
version = go1.16.7
serf_lan:
coordinate_resets = 0
encrypted = false
event_queue = 1
event_time = 2
failed = 0
health_score = 0
intent_queue = 0
left = 0
member_time = 1
members = 1
query_queue = 0
query_time = 1
serf_wan:
coordinate_resets = 0
encrypted = false
event_queue = 0
event_time = 1
failed = 0
health_score = 0
intent_queue = 0
left = 0
member_time = 1
members = 1
query_queue = 0
query_time = 1
```

Server info

```
output from server 'consul info' command here
```

### Operating system and Environment details

OS, Architecture, and any other information you can provide about the environment.

- OSX x86_64
- Running local consul agent in dev mode
- Following the consul [tutorial](https://learn.hashicorp.com/tutorials/consul/service-mesh-with-envoy-proxy?in=consul/getting-started)

### Log Fragments

**after modifying the intention in the web ui**
```
➜ ~ consul intention create -deny -replace dashboard counting
Error replacing intention with source "dashboard" and destination "counting": Unexpected response code: 500 (Intention lookup failed: failed config entry lookup: index error: UUID must be 36 characters)
```

**a different error if omitting the `-replace` flag**
```
➜ ~ consul intention create -deny dashboard counting
Error creating intention "dashboard => counting (deny)": Unexpected response code: 500 (cannot use legacy intention API to edit intentions with a destination of "counting" after editing them via a service-intentions config entry)
```

**server log from cli call to modify intention**

```
2021-10-19T14:41:24.744-0700 [DEBUG] agent.http: Request finished: method=GET url=/v1/connect/intentions/exact?destination=counting&source=dashboard from=127.0.0.1:53422 latency=89.901µs
2021-10-19T14:41:24.745-0700 [ERROR] agent.http: Request error: method=PUT url=/v1/connect/intentions/ from=127.0.0.1:53422 error="Intention lookup failed: failed config entry lookup: index error: UUID must be 36 characters"
2021-10-19T14:41:24.745-0700 [DEBUG] agent.http: Request finished: method=PUT url=/v1/connect/intentions/ from=127.0.0.1:53422 latency=73.32µs
```