Use appropriate Namespace/Typings for Firefox build

[martgil]

I think we can use an appropriate Namespace/Typings when building manifest.json file for Firefox - https://www.npmjs.com/package/@types/firefox-webext-browser

The project is currently reusing chrome's type definition:

flowcrypt-browser/tooling/build-types-and-manifests.ts

Lines 28 to 56 in fd0cc65

	addManifest('firefox-consumer', manifest => {
	manifest.version = version;
	// We decide to use manifest v2 for firefox and below codes are to make v3 manifest to v2
	// Read more here: https://github.com/FlowCrypt/flowcrypt-browser/pull/5651#issuecomment-2029591323
	manifest.manifest_version = 2;
	const manifestV3 = manifest as chrome.runtime.ManifestV3;
	manifest.web_accessible_resources = manifestV3.web_accessible_resources?.[0].resources;
	manifest.content_security_policy = manifestV3.content_security_policy?.extension_pages;
	manifest.permissions = [...(manifestV3.permissions ?? []), ...(manifestV3.host_permissions ?? [])];
	delete manifest.host_permissions;
	manifest.browser_action = manifestV3.action;
	delete manifest.action;
	manifest.browser_specific_settings = {
	gecko: {
	id: 'firefox@cryptup.io',
	update_url: 'https://flowcrypt.com/api/update/firefox', // eslint-disable-line @typescript-eslint/naming-convention
	strict_min_version: '112.0', // eslint-disable-line @typescript-eslint/naming-convention
	},
	};
	manifest.background = {
	type: 'module',
	scripts: ['/js/service_worker/background.js'],
	};
	// eslint-disable-next-line @typescript-eslint/naming-convention, @typescript-eslint/no-unused-vars
	const { service_worker, ...newManifest } = manifest.background as chrome.runtime.ManifestV3;
	manifest = newManifest;
	manifest.permissions = manifest.permissions?.filter((p: string) => p !== 'unlimitedStorage');
	delete manifest.minimum_chrome_version;
	});