fix: Max approval and array value spending cap bugs

[pedronfigueiredo]

Description

This PR fixes two bugs.

The first happens when the user approves a token for the max amount. This value is decoded by sourcify and is tipically expressed in scientific notation. However, this number has more than 15 significant digits. The fix is to coerce the number to a string (also accepted by bignumber js), forcing it to be expressed with 15 significant digits only.

The second bug happens because sometimes the decoded data from sourcify expresses a value of a param as an array of elements. An exception was added to the param lookup, so that we don't try to use an array value as the spending cap to be displayed.

Related issues

Fixes: #27535

Manual testing steps

First bug

1. Go to Uniswap
2. Select a token that hasn't been approved yet, and click to approve
3. The app shouldn't crash

Second bug

1. Go to https://ethereumfilm.xyz/ethereum-stories
2. Click mint on one of the posters or mini-movies
3. The app shouldn't crash

Screenshots/Recordings

Before

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]

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[metamaskbot]

Builds ready [ef82e3e]

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• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
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• code coverage: Report
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• all artifacts
• bundle viz:

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

Page Load Metrics (1876 ± 99 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	256	2414	1802	410	197
		domContentLoaded	1445	2399	1850	198	95
		load	1453	2402	1876	206	99
		domInteractive	17	69	31	14	7

Bundle size diffs

• background: 0 Bytes (0.00%)
• ui: 39 Bytes (0.00%)
• common: 0 Bytes (0.00%)