journal: Respect posting tag overrides

[Wheezily]

Fixes #1950.

Posting tag matching now treats explicitly set posting tags as overriding inherited transaction tags with the same name. Same-level repeated tag values are still kept; only inherited same-name tags are filtered out.

Validation:

• cabal test hledger-lib:unittest -j1 --test-options='--pattern=override' in haskell:9.8
• cabal test hledger-lib:unittest -j1 --test-options='--pattern=Query' in haskell:9.8
• cabal test hledger-lib:unittest -j1 in haskell:9.8
• git diff --check

[simonmichael]

Thanks for the PR, I have responded on #1950.

[simonmichael]

Hi @Wheezily, are you still interested in this PR ? These things would help it move forward:

• AI disclosure in the commit message, like https://hledger.org/AI.html#rules-of-engagement > 4.
• Tests/clarifications as mentioned in Inherited Tag Values are not Overwritten [💰$20 for 100% human contributions] #1950 (comment) and Inherited Tag Values are not Overwritten [💰$20 for 100% human contributions] #1950 (comment)

[simonmichael]

See also #1950 (comment).