feat: update tooltip for swap flow

[martahj]

Description

Updates the swap tooltip text and link.

The new text should be:

MetaMask doesn't make money from gas fees. These fees are estimates and can change based on how busy the network is and how complex a transaction is. Learn more here.

[“here” is a hyperlinkl that should link to help center FAQs on gas fees: Gas fees | MetaMask Help Center 🦊♥️ ]

Also updated how a variable was referenced because it was leading to crashes on the legacy swaps flow.

Manual testing steps

Swap redesign feature flag is here.

1. Disable smart transactions.

With swap redesign

1. Make sure the swap redesign feature is enabled in Test env
2. Start the swap flow
3. Mouse over the gas fee tooltip
4. Confirm that it now matches the above behavior

Without swap redesign

1. Make sure the swap redesign feature is disabled in Test env
2. Start the swap flow
3. Proceed to the review screen
4. Mouse over the gas fee tooltip
5. Confirm that it now matches the above behavior

Screenshots/Recordings

Before

With swap redesign

Without swap redesign

(this part of the flow is crashing depending on the value of the gasFeeEstimates variable)

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
66.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[metamaskbot]

Builds ready [3aec3be]

• builds: chrome, firefox
• builds (beta): chrome
• builds (flask): chrome, firefox
• builds (MMI): chrome, firefox
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• code coverage: Report
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5
  • common: 0, 1, 10, 11, 2, 3, 4, 5, 6, 7, 8, 9
  • content-script: 0
  • offscreen: 0
  • ui: 0, 1, 10, 11, 2, 3, 4, 5, 6, 7, 8, 9

Page Load Metrics (1681 ± 58 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	209	2153	1631	352	169
		domContentLoaded	1480	1964	1657	105	50
		load	1488	2063	1681	122	58
		domInteractive	22	166	43	32	15

Bundle size diffs [🚨 Warning! Bundle size has increased!]

• background: 0 Bytes (0.00%)
• ui: -2.04 KiB (-0.03%)
• common: 459 Bytes (0.01%)