[@angular-eslint/template/i18n] Prevent spaces at beginning/end of translated strings

[aleesaan]

Description and reproduction of the issue Sometimes linting rules can break the code into new lines in a way that adds spaces to the string to be translated, for example:

<button
  type="button"
  i18n
>
  Change password
</button>

Would end up in the string " Change password " being extracted, whereas I'd just want "Change password". I tried to use boundTextAllowedPattern for this, but I can't get it to work; from what I see in the source code we also trim() the string we test, so maybe that's why I can't get it to work.

Do you have suggestions on how to solve this issue?

Versions

package	version
@angular-eslint/eslint-plugin-template	17.2.1
@angular-eslint/template-parser	17.2.1
@typescript-eslint/parser	6.21.0
ESLint	8.57.0
node	18.18

# Please run `npx ng version` in your project and paste the full output here:
     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI: 17.3.3
Node: 18.20.1
Package Manager: npm 10.5.0
OS: darwin arm64

Angular: 17.3.3
... animations, cdk, cli, common, compiler, compiler-cli, core
... elements, forms, language-service, localize
... platform-browser, platform-browser-dynamic, router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1703.3
@angular-devkit/build-angular   17.3.3
@angular-devkit/core            17.3.3
@angular-devkit/schematics      17.3.3
@schematics/angular             17.3.3
rxjs                            7.8.1
typescript                      5.4.4
zone.js                         0.14.4

• [x] I have tried restarting my IDE and the issue persists.
• [x] I have updated to the latest supported version of the packages and checked my ng version output per the instructions given here.