output template: use text/template (#617)

# Description
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Previously we were using `html/template` which would result in strings
being rendered as escaped html

## Checklist
(For exoscale contributors)

* [ ] Changelog updated (under *Unreleased* block)
* [ ] Testing

## Testing

<!--
Describe the tests you did
-->

Before:

```
➜ exo dbaas show test --output-template '{{.Kafka.ConnectionInfo.AccessCert}}'                                                  24-07-04 16:08 
-----BEGIN CERTIFICATE-----
MIIEVzCCAr&#43;gAwIBAgIUCoWog7/IGKm3ts&#43;xO6kSfkk/UHwwDQYJKoZIhvcNAQEM
...
```


W/ this PR:

```
➜ go run . dbaas show test --output-template '{{.Kafka.ConnectionInfo.AccessCert}}'                                                                                        24-07-04 16:57 
-----BEGIN CERTIFICATE-----
MIIEVzCCAr+gAwIBAgIUCoWog7/IGKm3ts+xO6kSfkk/UHwwDQYJKoZIhvcNAQEM
```

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Bug Fixes
+
+- output template: use text/template #617
+
 ## 1.78.3
 
 ### Improvements

pkg/output/outputter.go

@@ -4,10 +4,10 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"html/template"
 	"os"
 	"reflect"
 	"strings"
+	"text/template"
 
 	"github.com/exoscale/cli/table"
 	v3 "github.com/exoscale/egoscale/v3"