chore: add safeMerge shared util

[taran-a]

Explanation

Add safeMerge shared util.
Use it in tron and solana snaps.
Add two test cases.

References

• Related to WPN-1817

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

[stanleyyconsensys]

not related to this PR

but can we add export of logger too? it seem missing?

[stanleyyconsensys]

Safe megre is actually:

Not a deep merge (only one level)
BigNumber is not support (it is fine, but since we use bignumber rather than bigint)
not support Date, Map, Set, empty arrays <-- empty array is more important

consider using lodash with a wrapper to handle null case

something like

import { isPlainObject, mergeWith } from 'lodash';
export const safeMerge = <TOverridee extends object, TOverrider extends object>(
  overridee: TOverridee,
  overrider: TOverrider,
): TOverridee & TOverrider=>
  mergeWith({}, overridee, overrider, (objValue, srcValue) => {
    // handle null case
    if (srcValue === undefined || srcValue === null) {
      return objValue;
    }
    // handle {}
    if (isPlainObject(srcValue) && Object.keys(srcValue).length === 0) {
      return objValue;
    }
    if (!isPlainObject(objValue) || !isPlainObject(srcValue)) {
      return srcValue;
    }
    // let lodash recurse
    return undefined; 
  });

but if we just wanna to limit up our usecase, it also fine, but worth to mention all limitation in the jsdoc